The only nerd rapper I listen to is YTCracker. Check out his album Nerdrap Entertainment System. All the beats sound like stuff from the Nintendo. Its way better than you would ever think.
http://www.ytcracker.com/nes/
I had a 92 accord with 17" momo's, a body kit, big fart muffler, cold air intake, blah blah blah. i sold that thing a week later. i couldn't hear my self think or the radio. it was like BWRAAAAAAAAAAAAAAAAAAAAAAAARRRRRRRRRRRRR!
i usually chop in acid then F with the sounds in Sound Forge or Fruity Loops. There are ton of programs that will do it, just depends on your preferences.
the monster relieved that he can stop peeing now pops open a Red Stripe, calls his granny and says, "ay mon, nutting bedda dan a good ole peehole pluggin'.
Use the piano roll. right click on the sample in the step sequencer and choose 'piano roll' there are tons of tutorials online and the help file is ok too.
michael j fox messes up the wiring and accidently wired the bomb to his own bowels. when the bomb goes a massive fart cloud spreads over the entire planet...