This topic was started a long time ago, so i know that the original poster probably wont read this, but for future wonderers.
go to your local thrift shops and get all types of records, you will find that different types of records produce different sounds.
childrens records such as sesame street is perfect! samples everywhere on those records, and great scrathing materials.
sound effect records are really good as well. I have many of these records that have sounds of the city, animal sounds, and just about anything you can think of.
for those who want to scrth on cd...
you can find these sounds easier with cd, I had three cds with about 100 sounds on them each (space sounds).
here is a tip! but keep this a secret, dont let this out guys!
for all those who use programs (serato, vdj, torq, etc.), sample a reaaaally short piece of whatever you want to scratch to such as fresh (just an example). lets say you sample the esh part, its gonna repeat over and over, now you dont even have to ue back and forth, you just have to cut with the fader. this is great if you want to lear how to crab, this way you can just focus on your crossfader.
try this and let me know if it works for you or whatever the outcome!