I think the best biography I ever read was Maya Angelou's I Know Why the Caged Bird Sings. I read it when I was 11, I think. My mom read it first, then gave it to me. There's some stuff about sexual abuse (from the victims point of view), but there's no glorifying sex and drugs. I don't know that a 13 year old boy would really want to read it, though. I have a feeling at that age a girl would appreciate it more. Kevin Smith has a new biography out, I've only flipped through it, but its basically a day to day account of his life over the past few years. Seems like it might appeal to a 13 year old boy.