In this video the guys at http://signaturesound.com/ is going to show you how to setup a compressor for any instrument, song, or genre and its actually a very simple process. It involves knowing which knobs to to turn, what order to turn them in and requires you to use your ears and really listen carefully.
To start off they are going to setup the attack and then setup the release, ratio and finally the threshold. Then go on to show you real examples within the video so you can get a better understanding of how to setup a compressor for different instrument groups. Remember to listen with a proper pair of monitors or headphones for quality purposes and to use your ears and train them for these scenarios.