Most of this is written for anyone new to the whole process, and it may or may not apply to you, but I think there's a few things that will clear up confusion after you get it "working" in addition to actually getting you started.

This guide does assume some basic familiarity with how to set up and run a station.

You have a dock, you have liquid and solid storage, and you have a (hopefully good, at least 3 star) manager... OK.

Go into the Logistic Overview for your station, and click the box at the bottom that says "Select Trade Wares". Pick which ones you want to trade, then set sell and buy orders for each one - yes you need both, and yes automatic is fine for now - except for the buy price, set that manually and as low as possible. Your ships ignore the price at your own stations, but this will prevent the AI from filling your stock (unless it's a very good deal, in which case... more the merrier, your auto-price for selling will always make a profit.)

If you absolutely don't want to buy from AI, there is an individual setting on each buy/sell order that allows or disallows trading based on a trade rule you can create under Global Orders in the player menu. There is also an option to set a trade rule under the station's Information screen. Don't do that, as it will prevent your station from trading at all. Again, if your buy price is set as low as possible that's pure profit as your sell order will always be at least equal, but usually higher.

I'd recommend hydrogen, silicon, and ore, but ignore helium and methane until later as you'll want to limit how much of that is mined due to the lesser amounts needed. Avoid ice. So little of it is needed that the AI will typically take care of that just fine, and it's dismal for profit.

If you must add helium and methane, be sure to set a very low limit. Personally I like about 10,000 as the upper limit to start, regardless of those millions of hydrogen I allow in fully mature stations. This is the limit mentioned in the buy order - it does apply to your ships, unlike the price. Setting your limit this way works, but the unused space will still be reserved even if it is never filled.

The better alternative is to set the allocated capacity - uncheck the box that says "automatic storage allocation" and either click/drag the bar where you want it, or click the number itself to type in the amount you want. This allows the station to use the space for the other wares you've left as automatic. Either works, but I recommend you set manual allocation limits. It will complain about this with an orange warning, for reasons related to production. As this station does not produce anything, this can safely be ignored.

Assuming you already have ships assigned to the station, reassign your miners and traders (you'll want mining ships for both, or at least something that can carry solids/liquids - not containers), so they get the updated orders - otherwise they'll be stuck with 1 sector orders to mine/trade nothing, as the station at the time wanted nothing, and the order failed (orange). You may have to do this a few times starting out as the manager's AI ramps up how much they need and how far the ships can go to get it.

A note about the orders... you will have to go through and trim it until its set correctly, as I mentioned. In order to do this you need to understand what the UI and orders are telling you. Normal operation should have a blue order (either mining or trading), followed by another blue or white order indicating what they're doing right now.

If there is any orange, something has gone wrong. If there is only a single orange icon, your immediate intervention is needed as the ship is doing nothing. Typically, if you have a trader that is stuck... assign it as a miner instead. Miner stuck? Make it trade. If they have an orange and blue order, it failed before, but fixed itself. I'd still go in and delete the failed order.

You'll have to adjust the balance of miner-to-trader as you go, but once you find that balance there should be no orange orders due to being unable to fill the station or sell the product, and everything will run fine without your intervention. The balance will vary based on how far each has to go to perform their tasks, but once the station is stocked (50-80% full), this usually equals out to 1:1 - one miner to one trader.

Also, keep in mind that if you are producing more than the stations within range consume that you will also see orange orders during the periods where your station is full, or no one is buying your materials, or both. You can either safely ignore them at this point, or assign them to a different station for better productivity.

A note: do not go overboard with your storage amounts. Ideally you'll be trading it away about as fast as you get it in, once your stocks reach a healthy level. The more storage space you have, the more your manager wants in the budget due to looking at those buy orders, and calculating cost. Yes, they're not actually paying it (usually) as your ships are filling it and not other AI, but they still calculate and keep that amount. I would suggest starting with a single L sized storage for both liquids and solids.

Further, if you have manual allocation limits set on a product (such as helium, or methane,) this will "increase" the cost compared to the equal split the automatic system gives as you set them. This is due to giving more space to the unlimited product (hydrogen, following the example). However, this is simply because hydrogen is more expensive, thus requires more cash reserve than methane or helium. If you compare a station that deals exclusively in hydrogen, to one that has a split and limits set, you'll notice the reserve budget is roughly the same, minus only the lesser cost of helium and methane.

If you want to collect your money manually through the Account Management tab in your player menu, that's fine, but if you set it correctly they'll hit their maximum... go above it by a certain %, and then automatically funnel you anything above that in regular payments - usually half an hour apart or so.
- NOTE: That is how it is supposed to work, though in 5.0 I have had issues getting them to do so, and mostly end up clicking "Accept All Estimates" under the Account Management tab of the player menu anytime I want to collect what they've earned.
- 6.0 Addendum: I have had great success simply giving them a 1 cr budget through the station's individual Logical Overview (though not through the global budget window), which they double to 2 cr, and then send all further proceeds directly to my account. It also does not work if you set it to 0, no matter where you set it.

Lastly... docking space - you're going to need far more than you think. I set mine up with Terran docks, and in a fully built station with 256 (the maximum) ships being managed, I fully use 6 docks. Terran docks have 8-10 small (I don't recall) and 4 medium spaces each. You'll need a lot more if you're using the standard 1m-6s (1 medium, 6 small) dock.

That's it! Good luck, and happy trading.