Some friendly advice I gathered for us new players:

Try not to play in games where the party is over 5 people. You'll likely get lost in the confusion. I think that 4 is the magic number.

Try to talk to the players in the game a bit before you start. A bad NWN game is twice as bad as a good NWN game is good. And a good NWN game can be AMAZING.

Try to play a character in personality and class that will be unique, and help the rest of the group with things they can't do. Having more than one type of class in a game isn't at all bad, but if you're not yet completely sure about your characters personality (or if the other player is just plain bad), some unhealthy competition might occur between the players (as opposed to between the characters, which could be good RP-wise). Much stepping on toes and pulling of beards.

Hm, these may only apply to me, but I write them anyway, should any new player come across this and might find it helpful.

Addendum:

Well, I won this award thing, and I'm switching over to the DMing/building side, so I guess I'm not such an utter newbie anymore, but all the above still count.