Good books about the story of hip-hop?

[IceBus]

I was wondering if anyone could recommend a book about the history and origins of hip-hop? It's a genre I've only really gotten into properly in the last five years or so, and I'd love to learn a bit about how it all got started and Wikipedia isn't quite scratching the itch!

Thanks for any recommendations!

 

[HamZilla]

Not books but the docu-movies Wild Style and Style Wars are essential viewing.