What I do want to say is don't over-compress. Some settings that I would use might go like this;
Band (all of these examples depend on the musician & there ability to control their dynamics)
Drums- I almost always put a compressor on my kick and snare (never on overheads. I use about a 3:1 ratio (for every 1db over the threshold, the signal is reduced by 3db) with about 4 db of reduction.
***One Quick note about compressors***
What I see many people do when using compressors actually defeats the purpose of it, and that is after setting a ratio, they don't properly set the makeup gain to nominal. Nominal is basically operating at the best level between a piece of gear and the board. (0db) What that does is covers up the noise floor, and at the same time keeps the signal from distorting. When you here tapes, and a lot of his, that is because the gain isn't at nominal.
Enough talk-back to the settings
Bass (Extremely dependent on player, especially during slapping)
4:1 - 6:1 ratio with about 4db-6db gain reduction
Piano - I don't use compressors
Organ - No compressor
Vocals - Normally put one on the lead vocals with a 2:1 - 3:1 ratio and a 3db reduction.
On your final stereo mixes, the style of song is the main factor. In todays music, (refering to the radio and CD's) our ears have become accustomed to smashed mixes (A LOT A COMPRESSION). But if you pop in a jazz or classical cd, you'll see a difference. So basically on your slow cuts, be gental.
Here are a list of some compressors I recommend;
DBX 160 (or just about any dbx compressor) they make about 50
the infamous LA-2A (very expensive but I promise you will recognize the warm sound it gives when you use it. Hard to find.
Hit me up with anything else.