Shades by Geoff Cooper and Brian Keene
Danny us a boy with an alcoholic mother who skips school to find crabs to sell for a new bike when he discovers a dead body. Only he was supposed to be able to see the body and the fact that he can is because of magic. And now he is learning magic from Gustav an eccentric old man to stop a dark magician from taking over the town one shade at a time. Suspenseful, interesting, and a powerful ride! I loved it. YA horror/fantasy.