"Release— When the signal level drops below the set threshold, this determines how long it takes before the compressor lets the sound through unaffected. Short Release values can result in intense, "pumping" compressor effects, while longer values result in a smoother, more natural change in dynamics"
from
http://safari.oreilly.com/1592006647/ch16lev1sec3
If you are willing to give FL Studio a try i could send you a simple file with a pumping compressor setting. Allthough the basics have been answered here before i think. Sure it's pump you are after??
I mean a little pump is ok i reckon but only to a certain extent.
Read this:
http://www.gearslutz.com/board/so-mu...breathing.html
http://www.harmony-central.com/Effec...s/Compression/
ftp://ftp.dbxpro.com/pub/PDFs/WhiteP...sion%20101.pdf