The aim of this guide is to enable you to see as much of the game as you potentially can in a single playthrough, to do that here are the goals going in:

• Obviously, everything here should be doable in a single, NG only playthrough.
  
• This will include access to or visiting all zones and bosses.
  
• We'll be aiming to complete as many quests as possible on a single character.
  
• Access to as many build-important items as possible.

And here are some secondary goals that I had in mind personally when constructing this guide that you can go along with or against at your whims:

• Access to as many items (generally) as possible, in other words I planned through this as much as possible to avoid locking you out of as many items as possible.
  
• Minimal/no covenant grinding.
  
• Since the walkthrough itself is quite minimalist, you'll want to be mindful of what items you'll need for whatever build you'd like to use and plan or adjust accordingly.

Character requirements in this game are pretty light with regards to seeing everything available:

• You'll need 15 Intelligence in order to be able to buy spells from Big Hat Logan.
  
• You'll need a Pyromancy Flame +10 in order to get Quelana to appear.

• There won't be any detailed walkthroughs for zones or strategy for bosses--there's hundreds of guides for that at this point.
  
• This playthrough ends Solaire's quest with his death from the Sunlight Maggot which only cuts out his conversation if he survives plus the ability to summon him for the final boss. If you wish to save Solaire the simplest way to do this is to ignore every step where you talk to Solaire (which will not advance his quest) until after you've advanced normally to defeating the Sunlight Maggot (or use the Daughter of Chaos covenant shortcut).
  
• Sif/Four Kings are delayed past the DLC in order to see the optional cutscene if you rescue Sif during the DLC.
  
• Steps marked with * are extra-optional (or have unusual, optional components eg Asylum Demon), obviously large chunks of the game and character quest bits are optional but these are often things that require specifically going out of your way to do if you'd otherwise want to just have a straightforward playthrough.

Bosses are denoted in [brackets].

Undead Asylum
*[Asylum Demon] Black Firebomb gift to kill during first encounter for Demon's Great Hammer

Undead Burg
[Taurus Demon]
-find Solaire

Undead Parish
-talk to Siegmeyer outside Sen's Fortress
[Bell Gargoyles] cut 1st gargoyle's tail for Gargoyle Tail Axe

Darkroot Garden part 1
[Moonlight Butterfly]

Undead Burg revisited
[Capra Demon]
-Return to Firelink Shrine to speak to Petrus, who is now joined by Vince, Nico, and Reah, check Firelink Shrine occasionally until they leave and only Petrus returns

Depths
-find Laurentius, avoid telling him about chaos pyromancy
[Gaping Dragon] cut tail for Dragon King Greataxe

Blighttown
Quelaag's Domain
[Chaos Witch Quelaag]
-earliest point you can interact with Eingyi

The Valley of the Drakes
-search Anastacia's cell in Firelink Shrine for a Black Eye Orb

*Undead Asylum revisited
*[Stray Demon]

Sen's Fortress
-find Siegmeyer
-find Big Hat Logan
[Iron Golem]

Anor Londo
-find Solaire
-find Siegmeyer
-invade Lautrec just before Ornstein & Smough
[Ornstein & Smough]
-find Siegmeyer at Firelink Shrine
-find Solaire at Sunlight Altar Bonfire in Undead Parish

*[Hellkite Wyvern] cut tail for Drake Sword

The Duke's Archives
Crystal Cave
[Seath the Scaleless] cut tail for Moonlight Greatsword
-buy all of Logan's spells to advance quest, defeat in the first Seath boss room, return to where he was selling spells for his items

*Painted World of Ariamis
*[Crossbreed Priscilla] cut tail for Priscilla's Dagger

-find Siegmeyer at Blighttown Swamp, give 3 Purple Moss Clump
-find Sieglinde outside Duke's Archive
-find Sieglinde at Firelink Shrine
Demon Ruins
[Ceaseless Discharge]
[Demon Firesage]
Lost Izalith
[Centipede Demon]
-find Solaire
-finish Solaire quest
-finish Siegmeyer quest
-latest point to get Quelana to appear; don't go defeat the Bed of Chaos without having interacted with her or she won't be available
[The Bed of Chaos]

*The Great Hollow
*Ash Lake

The Catacombs
[Pinwheel]
Tomb of Giants
-encounter Patches, answer no when asked if you're a cleric
[Nito]

Darkroot Basin
-after killing the Hydra quit and reload to spawn the Golden Crystal Golem and enter the DLC

Sanctuary Garden
[Sanctuary Guardian] cut tail for Guardian tail

Royal Woods
[Artorias the Abysswalker]

Oolacile Township
Chasm of the Abyss
[Manus, Father of the Abyss]

*[Black Dragon Kalameet] cut tail for Obsidian Greatsword
*[Sanctuary Guardian x2]

Darkroot Garden part 2
[Great Grey Wolf Sif]

New Londo Ruins
[Four Kings]

*-destroy the Gwyn illusion to access Dark Sun Gwyndolin
*[Dark Sun Gwyndolin]

-if you have not yet, buy all of Griggs' items to cause him to go hollow at Sen's Fortress

Kiln of the First Flame
[Gwyn Lord of Cinder]

Anastacia of Astora - found in Firelink Shrine

• will be killed by Lautrec after ringing both bells
  
• search her cell for a Black Eye Orb, use to invade Lautrec just before Ornstein & Smough
  
• then she can be revived at her cell

Big Hat Logan - found in Sen's Fortress

• found at Duke's Archives after 1st Seath encounter
  
• buy all spells + defeat Seath
  
• can then be found hollow @ room w/ 1st Seath encounter
  
• after defeating his hollow return to where he was selling spells for his catalyst and set

Dusk of Oolacile - defeat Golden Crystal Golem after the Hydra in Darkroot Basin, always answer yes, disappears during the DLC

Eingyi - found beyond hidden wall after Quelaag's room, answer yes to access bonfire, must be infested with Egg Head before he will sell pyromancies

Elizabeth - found in Oolacile Sanctuary, sells Dusk's items while she is missing

Griggs of Vinheim - found in lower Undead Burg

• hollows @ Sen's Fortress if you buy all his spells and items

Knight Lautrec of Carim - found in Undead Parish

• leaves Firelink Shrine after ringing both bells
  
• invading him in Anor Londo additionally drops his armor set

Laurentius of the Great Swamp - found in Depths

• after encountering Daughter of Chaos or Quelana, or possessing a chaos pyromancy, if you agree to tell him what you know he disappears from Firelink Shrine later
  
• is then found hollowed @ Blighttown swamp (does not drop any unique items and this locks off the items he sells)

Lord's Blade Ciaran - found at Artorias boss room after you defeat him, may give her his soul for her weapons (or kill for her set)

Patches the Hyena - found in Catacombs/Tomb of Giants

• can be encountered first in the Catacombs if Reah has not yet arrived
  
• encountered in Tomb of Giants later
  
• answer no when asked if you're a cleric
  
• moves to Firelink Shrine after Nito

Petrus of Thorolund - starts at Firelink Shrine; must join covenant to buy his miracles (or wait until Reah arrives)

• after ringing first bell and defeating Capra Demon, he is joined by Vince, Nico, and Reah
  
• some time after Reah arrives they leave for the Catacombs
  
• Petrus will return after some more time
  
• (talk to Lautrec to learn what happened)
  
• talk to Petrus to learn the truth

Quelana of Izalith - found in Blighttown swamp

• must be spawned before defeating Bed of Chaos, gives a Fire Tempest after you defeat it

Reah of Thorolund - found in Firelink Shrine after Capra Demon

• see Petrus for appearance
  
• defeat her hollowed bodyguards in Tomb of Giants
  
• will move to church in Undead Parish
  
• after some time Petrus will kill her (he will have her unique talisman
  
• if Petrus is killed before he can kill Reah, buy all her miracles and she will hollow @ Duke's Archives (drops Ivory Talisman)

Shiva of the East - if you join the Forest Hunter covenant he can be found in the Blighttown swamps selling several items with a bodyguard, who drops the Dark Wood Grain Ring

Siegmeyer of Catarina - first found outside Sen's Fortress before both bells are rung

• next in Sen's Fortress before changing boulder direction
  
• next in Anor Londo before O&S
  
• next at Firelink Shrine
  
• next near Great Hollow entrance; give 3 Purple Moss Clump
  
• find Sieglinde outside Duke's Archive
  
• talk to Sieglinde at Firelink Shrine
  
• next found in Lost Izalith before the Chaos Eaters; quest has 3 outcomes:
  
  • Siegmeyer helps you fight the Chaos Eaters, if he has >50% HP he is later found dead in Ash Lake (reward: Titanite Slab)
    
  • Siegmeyer helps you fight the Chaos Eaters, if he has <50% HP he gives you the Speckled Stoneplate Ring then dies
    
  • If you kill the Chaos Eaters before talking to him he gives you the Speckled Stoneplate Ring and otherwise survives

Solaire of Astora - first found in Undead Burg after Taurus Demon

• next in Anor Londo at O&S bonfire
  
• next at Sunlight Altar Bonfire in Undead Parish (kill dragon)
  
• next after defeating Centipede Demon
  
• finally in Lost Izalith near the Chaos Servant door
  
• to save him the Chaos Bug that drops the Sunlight Maggot must be killed before Solaire gets to the last location:
  
  • join the Daughter of Chaos covenant and level up to access the shortcut
    
  • kill the Chaos Bug through the shortcut door (eg large weapons, Poison Mist)
    
  • do not speak to him at Anor Londo until after you have defeated the Chaos Bug then proceed as normal
    
  • agro Solaire at any point then proceed to kill the Chaos Bug, then get absolution from Oswald and proceed as normal