Take a peek through live sound and read console manuals. As pflash mentioned, Mackie manuals are well-written.
However, if possible, I'd suggest finding a well-respected engineer who you could be a "go-fer" for, a mentorship of sorts.
Gaining mixing experience through hands-on learning, in a real-world environment, is very valuable. I know that I learned more from a few weeks of an internship than I did reading countless "Idiot's Guide to Mixing" books or whatever.
That said however, reading and understanding gear manuals is a big help.
To truly understand what's going on, you should familiarize yourself with your gear by scouring the manual.
To understand recursion, you must first understand recursion.
Colorado Club #77