First you got to manage your base. IMO a base standard should have 1 general storage +1 living quarter+1 small radar+1 large radar+2 Hanger. Alien containment is not necessary at the first 3 months coz the research priority is always about weapon at the beginning.

Equip your Skyranger with more rifles and less pistols. I normally manned Skyranger with one tank (Essential scout unit) & 10 soldiers. You don't need more engineer at the beginning so don't recruit more until you wanna mass production flying suit (not a beginning equipment). The rest of the space of living quarter all for scientist after enough solider for skyranger. Equip the interceptors all with missile, cannon is useless. Then you got to sell all worthless stuffs (Plane cannon & pistols) away.

In this game your big maintenance cost+purchase cost will be covered by selling alien's guns & materials. International funding will only worth 20%-30% of the total cost for your final victory.

Concentrate your research about weapon in the beginning. Research plasma rifle & heavy plasma ASAP to balance the firepower difference against alien. You can start the research only if you capture those weapon+ammo. You need to complete the research of both gun & ammo, then your solider will be able to equip & fire the weapon.

Soon you will meet your first battle against UFO. When you got tank in Skyranger, always let it run around your loading area to check out the condition around the skyranger. Don't use the gun of the tank unless you think that shot is truly critical. If you see there is enemy around the loading area, put your men down to kill them at once to secure a perimeter around Skyranger.

If the battle is at night you will need to throw Electro-Flare to light up the field. Each Skyranger should equip one Rocket launcher until you are able to equip Alien's Plasma rifle & Heavy Plasma, coz out of those 2 powerful guns this is the only weapon for human against early alien's terror unit heavily armoured Cyberdisc (In early stage you will see it only when Alien's terror attack against city). Auto Cannon with incendiary ammo also very useful for lighting in the night time combat.

After perimeter around Skyranger secured, let your tank go further search for more enemy & your soldiers will expand the perimeter. When the tank find enemy, your soldier from behind can shoot the enemy if the line of firing is allowed no matter that soldier can see the enemy or not.

After you complete the searching/scouting field you should be able to locate the UFO. Let the weak rookie get into the UFO first. When you see any alien shoot at sight. Small & Medium scout UFO both got simple internal structure. For Large scout UFO you will need pincer tactic by 2 soldiers on left & 2 others on right to storm the cockpit.

After you did the research of plasma rifle & heavy plasma, the combat will be far far easier coz alien weapon not only more powerful but also far-far-far more accurate. There is a trick (not cheat) to save your plasma ammo. Before you storm the UFO, the soldiers never fire a shot go to grab alien's gun already fired once. This game will forfeit the ammo magazine already fired even just one shot, & only take totally unused ammo magazine back to base. The combat will not end until all aliens are dead/captured.

Summary of useful techniques in ground battle:
1) To save more Plasma gun ammo, pick up the already used gun from dead unit (no matter human or alien) instead of holding a unused gun if possible. Of course always concern the safety of soldiers in top priority.

2) Shoot out of enemy sight - When your scout (mostly meaning your tank) find enemy, try to use your soldier behind shooting instead even the target is out of the sight of your soldier. Your enemy will not return fire to your soldier out of its sight, but you can shoot it when the line of firing is allowed.

3) Hit & run - entrance of the UFO may be heavily guarded by multiple aliens too many to be killed by single soldier. You can mass your man behind the door, & let every soldier walk in the room->shoot->exit back out of the door. Each soldier top priority target is the alien facing the door so that you got to kill the one may be very likely return fire. By rotating your soldiers behind the door you can secure the entrance by teamwork. But be careful it may have potential dangerous that alien may use explosive weapon (Alien Grenade or blaster launcher) to kill all your soldiers behind the door by one single blow.

4) One more step behind the door or corner - you will know it is risky but necessary to search behind the door or around the corner. But when your soldier is lack of time unit to move on, you will stand beside the door & corner wait for the next turn. Don't stand just next to the door or corner according to my experience. Position your soldier one more step behind may let alien coming out harder to locate you so that your soldier will be safer.

After your first battle you will get many Alien's equipment & materials. Keep all alien guns & grenades. Then only keep 10 Elerium-155 & 10 Alien Alloy & 1 UFO powersource & 1 UFO navigation for your research & sell all extra. If you found you got more alien gun than its ammo, sell the extra guns too. Always put Plasma rifle+ammo & Heavy plasma+ammo to top priority in research. You will know the time to keep more Elerium-155 & Alien Alloy when you are able to produce Plasma cannon for interceptors & Flying Suit for your soldiers. You may need to build more storage room for materials reserved for production.

In next month February, you should try to build your second base at once. Follow the 2 hanger+1 storage+1 living quarter+1 small radar+1 larger radar to build your second. If your first base not protecting USA, you better build your second base at north america instead. After 2nd base functional you can build extra living quarter x1 and laboratory x1 in your first base to speed up research. Build workshop in 2nd base & then transfer all 10 engineer to 2nd base, so the living space of 1st base all for scientist & let 2nd base will do the production instead.

When you research speed is doubled (about 80-100 scientists), you can start build the alien containment. The path to the final victory is, keep capture high rank alien until you know the location of the alien final base. The game end when you destroy alien's final base. You will need Mind Probe to identify which one is high rank alien & worth to capture. Stun rod is useless you will need to research alien's small launcher & stun bomb for effective capturing.

There are some techniques after the beginning stage:

1) You don't have to shoot down UFO. You can let Skyranger follow the UFO till it landed. Capture a complete undamaged UFO & sell its fuel & equipment can generate far more money than international funding.

2) When you find alien base in beginning stage, don't storm it but use it lurk more Alien supply ship. Capture every supply ship will finance you far far more better. Alien is trying to fund you in better way when they establish a base on earth ^^.

3) You will use Alien technology to make better craft. You will need UFO powersource & UFO Navigation for such advance crafts. As now you know how to capture undamaged UFO or even farming from Alien base. You know those two things not worth to produce by human at all ^^.

4) After the 2nd base you may not need to build complete set of base, but only radar station. You can build a base with only radars to extend your UFO detection coverage. (But my game normally need 3 bases with skyranger, to train more soldiers for the final assault against Alien final base)

5) You will meet Psychic attack type Alien at the latter stage (you will got tech to identify their UFO). Avoid ground battle against them by using interceptor follow their UFO to sea area, then shoot the UFO down to sea.

6) Blaster Launcher + flying suit will let you storm large size UFO far easier, by blast a hole out of UFO's hull. When fighting against battleship of Psychic attack type alien, you will blast the hull out of battleship's commander room to kill/capture alien commander as the 1st move (I don't wanna spoil the location of commander room, play & locate it yourself). After you kill the commander, whole group of aliens will be highly demoralized so that their power/threat of psychic attack will drop dramatically.

Hope my words can help. Have fun ^^.

Technique:
1) Suicide bomb - I think beginners will struggle how to storm into a room sitting many aliens (eg. Medium Scout UFO) without advance armour & alien weapon. One way to simply kill them all by sacrifice a weak rookie soldier is suicide bomb. Before get into the door, let that sacrifice soldier hold a grenade and set timer to 0. Then let the sacrifice soldier get into the door and walk to the middle of the room without firing a shot but holding the grenade. It is no problem if alien shoot him down on his way walking. When the turn ended the grenade will explode and kill every alien around the grenade.

After you develop mind-control weapon, you can do the same thing to the alien under your control.

2) Easy fortified Skyranger with flying suit - before flying suit everyone will struggle how to secure a perimeter around skyranger. But if you got flying suit it will be very simple. Just let 2-3 early exit men fly up on the wings & body of skyranger, then you will easily secure the perimeter around with high ground advantage also. If the soldier is sharpshooter guarding on skyranger, you can let him knee at the end of the wing as sniper (Knee posture can increase the shooting accuracy). With the power of heavy plasma + over 80% to even more than 100% accuracy shot out of enemy sight, you will easily slaughter aliens unless you are under mind-control attack.

3) Shoot a way out pass the wall - Plasma weapon can easily destroy a wall in human city. During anti-terror mission you can point & shoot the wall in front of you, to open a sight for shooting alien behind the wall.

4）Very large UFO - only alien battleship is in this size. Its guns are outrange the plasma cannon but fusion ball is not worth to use. So the best way to deal with battleship is let your skyranger follow it till it landed. But ground battle against it also is a hard battle (but worthy coz one battleship is very very very resourceful ^^). The most dangerous thing in ground battle against battleship, is there will be at least two aliens equip devastating blaster launcher. Today I played against a snakeman battleship, one blaster bomb targeted my tank and exploded a huge area killed two other soldiers. Its internal structure is also highly favourable to defenders. If you can use blaster launcher also it will be far easier to play against battleship. You can breach a hole from one of 4 engine room (beaware the explosion area may kill your own soldier), and create a far more safe/secure entrance than its main entrance. Searching inside the battleship is quite challenging. You better take 2 soldiers as a team & guarding hallway instead of intersection by standing back-to-back.

Opinion:
a) Difficulty setting - Game difficulty is only about how many UFO sent to earth & how many aliens on each UFO depending on the type & size of UFO. So actually playing beginner mode only mean you will encounter less UFO and aliens. But since it is important in the game to take alien guns equip your soldier & sell alien material to make money. So encounter too few alien will only make your battle easy but difficult in finance for origanisation expansion. Veteran level is already very balance for beginner IMO.

b) Save & Load - I found someone suggesting using Save & Load during ground battle to avoid casualty. For beginner I think save & load is okay but please don't do it during the ground battle. Ground battle is the main origin of fun in this game & normally its most crucial part is to locate aliens before kill them. If once you located alien after your soldier killed, and you just load back the battle & walk around the alien you already located. I think the major fun of the game will be spoiled. I suggest beginner try to carry on the whole ground battle. If the casualty is too big to take, learn from your mistake & rather reload from the point before that battle started instead of the point within the battle & you already located the alien killer. This will make your game more meaningful.

c) base defense - in very rare occasion alien will attack your base. Your scientists & engineers will not help you fight against alien but only your soldiers. Alien will come in through access life & hanger only. So when you build new base you better place hangers & access lift together in one direction away from your living quarters, so that your soldiers won't facing threats from multiple directions. Attackers may release alien prisoners once they unlock the alien containment, so you better place alien containment far away from access lift & hanger. Normally I will build hangers & access lift on one end then living quarters in the middle, then alien containment to the other end protected by soldiers in living quarters.

1) When you go into ground battle when another X-com craft encountering another UFO, You will get a looping error. In this condition after you win that ground battle, you will loop back to the end of ground battle you already won when the engagement of the another UFO ended (Landed/shoot down/disengaged are getting same loop). To avoid such error, disengage all other UFO(s) before getting into a ground battle.

2) Save after destroy final boss - Actually when you killed the final boss then press the end turn button, you should see the final victory ending. But if you save the status of ground battle after you killed the final boss then quit the game there will be a bug in that save file. When you load that ground battle that final boss already dead, you can't see the final victory ending but the battle just keep going turn after turn. So if you wanna able to re-watch the final victory ending, you should save the moment before you give the killing blow to the final boss instead of the moment you already killed it.