Watched an amazing documentary today on scratching. It's called Scratch. Yup. It's all up to watch on Pitchfork.com to watch free for the month but if you miss it I'm sure you can figure out where to find it yourself.
It features interviews with Grand Master Flash, DJ Premier, DJ Shadow, Afrika Bambaataa, Steinski, Grand Master Theodore.
It covers chapters on Turntablism, Battling, Making Beats, History of DJing, Hip Hop culture, loads of stuff!