The Etrian Odyssey had quite a bit of reading, but not books worth, and it was always broken up into smaller chunks inbetween gameplay.
As far as I know, people like reading novels, so whatever you do, it cant be bad.
People like reading good novels. Uh, well, alot of people like reading Twilight and Eragon, and those aren't 'good', so I guess that disproves that. Harry Potter was very enjoyable, but it wasn't particularly well written (the world and plot were interesting, but the writing quality itself was merely average, and the characters were above average, but not fantastic. Still was enjoyable though, and apparently about a third of a billion other people also thought so).
@Syrena: If you are going to have alot of writing in your game, I suggest you get it peer-reviewed by a two or three people, and get some heavy constructive criticism to refine it and refine it some more (then have the same three people review it again, to give more advice and critique the changes).