Although this guide is still "useable" the new version takes account to some of the suggestions posted in this thread!
Happy Building!

First of, you will need a TS ship, so after completing the first mission, fly back to Argon Prime and fly really close to the docking clamps of the Shipyard. Eject all your cargo and equipment into space, you’ll need it later! You will then need to exit your ship.
When you have exited your ship, you will need to target it and enter the command console. Then order the ship to dock at the Shipyard.
Now you must target the Shipyard and comm. it to request landing permission. A green circle will appear where you need to go. When you have reached the green circle, you will have manually docked the shipyard.
Your ship should arrive shortly, if it hasn’t already docked.
Now trade with the station and sell your ship, then buy a Mercury (don’t buy any equipment except for the trading system extension). Change ship so that you pilot the Mercury and then head off to reclaim you equipment from your starting ship (you can find all the positions in the sector map). I advise to get the SETA first.
When you have reclaimed all of your equipment, you’re ready to begin trading. Head south past Home of Light into Ore Belt and set course to Solar Power Plant there, buy as many Ecells as possible, but only if the price is below 14 credits (I only buy them at 12 credits), then explore the sector until you have recovered some ore mines, check the details of the stations in the sector to get the best sales price for the Ecells and sell them.
When you have made enough trade runs with Ecells, begin trading with ore to the weapon producing factories scattered around Argon space (Red Light, Argon Prime and many others) Only buy ore if the price is below 70 credits, you may get lucky and sell to over 150 credits! That’s over 100% profits!
When you have accumulated about 700.000 credits, go to the shipyard and buy a Discoverer L (so you don’t need to waste time in searching for equipment!). Change ships to the Disco and order your Mercury to go to the Terracorp HQ in Home of Light.
When your Mercury has docked, go into the trade with station menu, and buy the Trade Software MK3.
Then enter the command console for the Mercury and select Trade -> Start sector trader (ST) Select a sector for which the ship will trade eg. Home of Light and you have just started of your first autonomous trade ship. When the ST reaches level 8-10, you can select the start universe trader option in the trade menu (UT). When you do this, your trade ship will travel the galaxy looking for the best deals by himself and make money for you.
You can now use time in exploring the galaxy sector by sector while your ST/UT makes a steady income. When there’s about 800.000 credits in the bank, buy a new Mercury L and send it of for Terracorp HQ for a Tradesoftware MK3 and start your second ST.
Keep repeating until you have about 10-15 ST/UT ships flying around.
You should now make about 10-20 million credits pr hour on SETA, it’s now time to buy your very own TL. This is a lot easier than hiring since you can equip a jumpdrive and instantly go to the desired sector.
You now have a small fleet of trade ships and a semi capital ship, now you can begin with placing factories.
Select a random sector and check the trading station there. Look for any wares with 0 in stock. Now check the neighbouring 2 sectors on all sides for factories producing these wares, if none exists, you will have found a good spot for a factory.
Use the above technique and you will quickly amass more income than you can spend!
A few tips.
When buying factories, always buy 1 Trade ship (TS) (with assigned homebase to the factory) for each resource to buy, and 1 TS for the main selling product.
When buying ships with turrets, always enter the command console and issue the order of choice to the turret or it will not fire!!!!!
As this is my first guide, I may have overlooked something, feel free to enlighten me