Every good DJ knows to check his kit is suitable for the job. Try a baby scratch : which is a quick push forward and pull back with your middle, index and ring fingers. If the needle jumps then I'd suggest a heavier cartridge or a lighter counterweight (try HARD TO FIND RECORDS). You also need to have some vynil that are sutable for scratching! One of the first records I ever scratched was Jesus Christ superstar! You don't even have to think about the results. It ended up like K.kkkking King Of The JJJJewws! Hehehe. But joking apart you are gonna need some decent vynils (see nuying music). Now I don't really know much scratching so you'll have to check out Dj Recess's page becoz it rocks (RECESS.CO.UK).