Newbie question about loading sounds & samples

I just sold my CD turntables & am getting into the sampling & beat making phase. My quick question is this, I no longer have my tables & need to know since I have a Mac G5 1.8G can I start creating beats finding samples from my iTunes music?? I mean digital music is digital music, whether I load it from CD turntables or from my iTunes Library, right??

Sorry, I guess it would have been helpful to let ya'll know what Akai I have or want to get. I plan on getting supposedly the most user friendly mpc1000.