If I play a paladin, which god is helping me? It doesn't say in the bio. I know it's not that important gamewise, but I was always wondering this. Anyone know?

In the Realms, it's usually Tyr or Helm.

I always figured that a paladin by definition was a warrior who dedicated his life to the service of his god....Could this not mean that they could be of ANY alignment or serve any god...

I, too, think that's kinda weird. If you follow Tyr, Torm or Helm, you can be a Paladin and get your special Paladin abilities and all that, but if you're a Warrior-Priest of any other stripe, you have to be a Fighter/Cleric and can't stab anybody any more.

apparently they fleshed this out better in 3rd edition rules making a paladin a subclass of cavaliers.

Torm is the god of paladins, although it's handled strangly

Technical, you could say that Paladins are warriors that serve good (or for Helm, neutral) alignment gods such as Ilmater, Torm, Helm and Tyr. However the main gods that Paladins serve are Tyr, Helm and Torm. Their statures can be seen in the MNOotRHeart's building. Does this answer the question?