I'll try and make this post shorter and more coherent.
Books on culture for each main people. (Elves, Dwarves, humans)
Books on religion, one per continent should work (Jaiman, Emer,...)
Lots of detailed information on where they live, specific cultures and customs, their religions and worships)
Previous works have been great for an overview but I'd love to see grassroots details.
Thank you for listening, I realize my wishes might not coincide with the wishes of the masses.