Grunherz - basically you pick a race, pick a profession, and try to become expert at it. The game is run off of various terminals where you bank, get missions, travel between place, and craft items.
For instance, one of my characters in an artisan, human. I go out into the wilderness and get resources like steel, petroleum, and ore. Then I take those items and make a pistol which I can use, give away, or sell. I get experience for all these things. Eventually I'll be able to make battle droids, build houses, and set up harvesters to do all the hard work.
Other professions are more exciting - you can be a marksman, scout, bounty hunter, or dancer/musician.
Eventually, you can choose to fight on the side of the Empire or the Rebels and then you'll get missions to fight the opposing side.
That's a nutshell view, there's alot to it (and alot wrong with it, I'll admit).
