Dwarves have a monotheistic religion, driven by tradition and prophesy, that has schismed into two churches that can be considered analogous to the Catholic and Orthodox Christian churches.
Elves follow a shamanistic system based on totem animals.
Humans worship their ancestor-heroes, in the system most similar to the standard D&D pantheon.
Goblins worship their clan leaders as gods, similar to Egyptian pharoes.
Coivalds (from Mythic Races) worship nature (it may be more accurate to say that they worship a god whose completely coterminous with the world). They invariably become druids rather than clerics.
Sandesti (also from Mythic Races) worship elemental forces in the forms of sand (earth), river (water), sky (air), sun (fire) and moon (spirit).
The problem I'm having is that I can't think of anything to do with gnomes. To be honest, I've been kind of drawing a blank on them for more than just religion. I'm half-tempted to drop them as a race altogether, but I do like them, and I'd rather keep them, if I can just think of a decent handle...
If anyone has any ideas, I'd be glad to hear them.