Okay, not really a book, but I've been listening to a couple dozen Twilight Zone radio dramas. I think I've listened to some before, but I went through a whole collection I had on the computer, plus a few from the library. Fun little mini-stories usually science fiction.
I think the strongest lesson I learned is to be very careful with your wishes if you're granted a magic lamp, and to be careful not to break your time-stopping watch. As for some of the other stories, well... be careful with time travel, and be nice to others.
I'll peg this at around 300 pages, since it took a couple weeks to listen to, and that's about how long a 300-page book takes.