It's nothing new in terms of game layout, so if you're familiar with KOTOR, Mass Effect, or Neverwinter Nights, you'll have no problem getting plugged in. You have the class system & skill trees as well as specialization. Your actions can gain or lose influence with party members, although you can give gifts to them to help you with influence.
Throughout the game you can choose whether you're in third-person(like KOTOR or Mass Effect), or zoomed out (like NWN).
I will say Dragon Age: Origins is a little tougher than other Bioware RPGs. Area of effect spells can damage party members, so you have to watch your surroundings and be certain party members are out of the way.
Only con I can think of is that there is too much dialogue. Fortunately if it's getting on your nerves you can just hit the ESC key to skip most of it. Other than that, definitely worth it to play!