Fiction by Scott Westerfeld.
Afterworlds is a story-within-a-story, a young adult novel imagined as if it were written by an actual eighteen-year-old. So the story is also about the writing process as well, which makes this novel unique and interesting.
I really like Scott Westerfeld; I recommend the "Uglies" series, all four books, if you haven't yet read them.
I also read recently by this author: Leviathan, Behemoth, and Goliath