I've read that this has been suggested, but I'd like to post my ideas on the subject.
First off, I'd like to start out with reasoning behind what will come later. Books are the pinnacle of collected shared and collected knowledge in the real world. Even today the internet could be said to be a giant book that is consistently being altered and edited. This is why I feel that books should be added into the game and should not be taken lightly.
So I'll start off by saying that I feel that books should require an investment into not only reading them(easiest) but writing them (hardest).
So lets start with the creation. After ascertaining the correct intelligence and skills required to write the novel or how-to manual, one would then need regents as follows: Hardened leather+bone glue+String+Large amounts of parchment
The book would not simply be a book ready to be read by an individual at that point. The new (Empty) book would then need a station of sorts where one would have to spend at least 2 in game days at writing in the novel. This would be cumulative, where if you left it, you would simply pick back up at where you left off.
To compensate for this, I feel that books should have the highest LP/hour ratio in the game, be reusable (Not the same book twice), and have a high intelligence/skill to be able to understand it (Comprehension)
Why I feel that it should be reusable as a curiosity and so powerful is because a book doesn't just simply disintegrate or disappear when it's read, but having it permanently marked by an individual as read would make it so a new book would have to be acquired. This would also grow the chances of village libraries or how novels are passed from one individual to the next, much how they are in real life.
Just as it takes a person some time to read a novel, it should in the game. Not only should it have a lengthy time requirement, but a skill, like comprehension, to be able to understand what is written. As in real life, one can read in black and white, or one can read in color. The difference of the two is indescribable.
So to summarize: Books=Highest LP/Extremely long creation time and heavy investiment.