Captain Underpants is definitely a book and not a comic book. Sure, it's for preteens I'd say, and the comic book parts of the book are entertaining, to me at least. Comic books don't cause illiteracy; they require reading, silly! Plus they often reflect what society views as a hero. They're like the new myths of our day, instead of Hercules and Achilles and that old stuff.
I'm reading the Diary of Anne Frank, the play version. I might get a part in it at school.