uhh right now I'm just going from my soundcard to a mixer, then the record out to the MPC where I sample it. this leaves much to be desired. i just have a crappy soundblaster and the quality really sucks on it. if you have a good soundcard i'd assume it'd be fine, but damn its full of hiss and shit on mine. what i'm going to do is hookup my ZIP drive with a parallel port into my printer slot on the comp, then hook up a SCSI zip i just won off ebay for like 5 bucks plus S+H into the MPC. Then I'll be able to just drag sounds into the zip on the computer, pop out the disk and load them into my MPC. Or so I think.
http://www.youtube.com/watch?v=G96ij7Z4fMA&search=MPC
thats the video I mentioned earlier on actually hooking up reason to the MPC with midi and all that. useful stuff, but i'm waiting till i setup the studio in my new house later this month to do that.