Yea pois. Rexigar broke it down pretty good. i would however recommend starting out with a straight up DPS class first, while you are learning the mechanics of the game and the roles of the players. this leaves you with two options, ranged DPS or Melee DPS. the advantage this game has over most other MMO's for me is 1 STAR WARS nuff said and 2 the story line/ leveling grind is very enjoyable. it's all voice over dialog scenes where you get to make decisions that affect how things play out.
Now this is my own opinion but to me MMO's seem like 2 games in one. the first is just starting a character out and leveling them up 1 to whatever level cap happens to be depending one the expansion. which is usually the boring part of the game. and 2 End Game content this is where you start grouping up with people to attack harder stuff that rewards you with better gear and weapons. once i hit this point of these games it becomes much more enjoyable for me. in other words i love grinding for gear not XP.