In Book of the Righteous, you get a complete pantheon of over 20 gods, mostly good and some evil. With each god, you get a description of their place in the mythology (and it has a very mythological feel), their relationship to the other gods, and a throrough description of their churches, including titles, structure, core beliefs, and religious laws.
Each god has 3 holy orders: the cleric, the holy warrior, and a prestige class for each god. It's interesting that the prestige classes are generally NOT designed for the clerics or holy warriors. The god of magic has an archmage type prestige class; the god of travel has a messenger/courier prestige class that works best for rangers or rogues, and so on. The prestige classes are very well done; interesting, lots of abilities but not overly powerful.
There's roughly 10 pages of material for each god, and NO stats for the gods or their avatars. These gods are a bit more aloof than, say, the deities of the Realms. For example, for Terak, the god of war and valor, there are two schools of thought with regards to his alignment; some see him as lawful good, while others see him as lawful neutral. I thought that was a nice touch; gods are not completely known to man, but rather shaped to suit the purposes of the church.
The pantheon is heavily slanted towards player use, with good and neutral deities. There are only 4 evil deities, who are there primarily for DM use.
If you've got any other questions, Xarlen, just ask.