Two classic sounds here! The Roland 808 rhythm machine and the wilhelm scream. You've heard them both before, I gaurantee it. ;D
SOME QUICK RULES ==
808 must be treated somewhat natively to itself. You can not trim, pitch shift, or otherwise edit the 808 samples. You may only trigger them. Each percussive sound should get it's own channel in your DAW or tracker and a new note action (NNA) should end the current sound. Effects applied must be universally applied to all 808 channels/sounds. There are a lot of variations in the bitpack on the kick, snare and others. Treat it like it's an actual chunk of hardware with one output.
With the Wilhelm scream you can do anything. That's where all your harmonic samples will come from. That is, unless you trigger the 808 drums so fast it causes a granular pitch . . .