Most needed books are kept in the quest items tab. 99% of the books are not required for game completion, they offer back story, lore or pure entertainment such as the troll survival guide you can find in the tavern. Some books hint as to what happened to some of the races since Divine Divinity. (Originally called Divinity: Sword of Lies)
Yes, but there are a few non-quest books, like the couple I mentioned, that
do have clues on how to solve some non-essential quests in the game. Took me a second playthrough to recognise that some of those books are useful.
