Long time X-player (X-tension, X-2, X-3 Reunion) chiming in here.
Lionheart asked about 'auto-trading'; first get a piece of software called a trading system extension and install it in the ship that you're piloting. Now you can check pricing and stock levels of a station without landing; target the station, check the info, and the quantities of stock for sale and resource inventory levels and current prices are listed. You can now also order your freighter to land at stations (you don't even have to be in the same system; once your freighter enters the system you have access to price and stock information) and buy and sell items while you continue exploring the galaxy in your other ship. You can also purchase trade command software Mk. 3 (later, when you've got the cash because it costs over 500,000 credits). This will eventually (after your pilot learns and increases his trade level) make your traders almost completely autonomous.
Here is a link to the Egosoft forums:
http://forum.egosoft.com/index.php
When you go into the X-Universe forum check the The Ultimate X resource and guides list (it's a "Sticky" thread right near the top). This thread contains links to tons and tons of information about all the X series of games.
Also, here are a couple of other sites with tons of information as well (including sector maps, etc.):
X-3: Reunion
http://www.xdatabase.de/x3-reunion/en/welcome.html
X-3: Terran Conflict
http://eng.x3tc.ru/
Warning: Visiting these sites is bound to lead to spoilers eventually, but sometimes you may find yourself needing that extra little bit of information.