started to teach myself. i bought a P Love dvd, it's ok to explain the technical aspects of scratching but the best way I've found is to keep practicing, eventually you'll pick up a few tricks and then it'll grow from there.
Get some good scratch material, DJ Rectangle volumes are quite good or even just old pop records or film sound tracks.

I've been practicing to HardStyle, making up melodys that fit the tune, i've found the faster the music, the easier it is to scratch too, but I think that's maybe down to the way I've been scratching, using the record more than the fader.