2e was fantastic for this:
Complete Priest's Handbook (introduces forces and philosophies, and underpowered followers of generic archetype gods)
Legends & Lore Fleshes out the 1e Deities & Demigods human pantheons with much more lore, including nontheistic Taoist and Confucian spellcasting priests.
Monster Mythology nonhuman counterpart to L&L with demihuman pantheons, humanoid ones, giant ones, and gods for things like beholders, illithids, vampires, and fey courts.
The
Forgotten Realms Adventures hardcover with a bunch of FR deities with their own specialty priests.
The Forgotten Realms trilogy of god books, the high point for me of D&D god books,
Faiths & Avatars (core major gods),
Powers & Pantheons (demigods and Egyptian and Babylonian pantheons), and
Demihuman Deities (demihumans including drow).
For Greyhawk there was the
From the Ashes setting boxed set with a section of similar style entries for the Greyhawk deities that I never really read through, having been thoroughly familiar with the 1e setting gods and my reading at the time focusing more on the setting changes.
And for Birthright there was the
Book of Priestcraft which does the same for the gods of the Birthright setting and which I eventually got as a PDF but have not really delved into.
I couldn't say if any of the 2e Dragonlance setting stuff had similar things for the Krynn deities.