I also should have mentioned this book yesterday because I loved it as well.
The Graveyard Book by Neil Gaiman is a fabulous read for teens about an toddler whose family is murdered in the first chapter but who escapes the same fate by wandering into a local graveyard. In the graveyard he is adopted, raised and protected by its ghostly residents. The story follows the young boy as he grows up moving between the worlds of the dead and the living. Fascinating, clever, and a quick to read.