Okay I know you get to choose who you get as your animal companion if you're a druid or ranger. But do you get to select what familiar you have as a sorcerer or wizard? And could someone please tell me all the special abilities each familiar has?

Thanks in advance.

Yes, you get to choose them every time you level up. And: http://www.sorcerers.net/Games/NWN/animals_familiars.htm - though this is for the original NWN only, without any expansions.

Extra animal companion (added in SoU IIRC):
Dire Rat: can disease opponents that are hit by it's attack. The DC increases with Class level of master.


Extra Familiars in SoU:
Fairy Dragon: Has stunning breath weapon with one use which gets additional uses at higher levels. Also gets some uses of Improved Invisibility at higher levels.
Pseudodragon: gets use of fire breath weapon at higher levels. Also has an undocumented poisoning added to his attacks.

Extra Familiar in HotU:
Eyeball: I think this is how it's called. Not sure though but it is a kind of Beholder but I don't remember any specifics. I think he gets some kind of Beholder rays but I'm not sure.

It says that he (the Eyeball) can cast spells, but it doesn't list the spells it can cast, and it always stays FAR from the enemies. had him run off screaming when I encountered a dragon!

Considering familiars, does the patting, scolding, and playing with it affect it? I know feeding it restores health, but i havent noticed any changes when i do all the other stuff?

Since I'm going for the arcane archer, my guy is both ranger and wizard. I got to choose wizard familiar for him at level 1 (chose a panter), and I got to choose the ranger companion at level 5. (Chose a bear.) These two are great as tanks in battles, while I stand behind them and fire arrows.