Hmm, I think the books aren't too bad as they are, though forgetting to change books usually results in great losses, but that's life. Maybe adding some book mastery, as in, after a certain number of uses of named book and a certain level of INT (which is, as least stat description-wise, the stat you use to learn from books), you shouldn't quite need to use the book. Would be annoying to make from the dev part, agreed, but how after a few years of using the same book a guy still can't do it on his own is a bit.. weird, wouldn't be if the guy would be stupid, but otherwise, strange.