Wil - it's hard to say how long it would take to 'train' someone. In terms of the technical aspects, anyone with strong IT skills, and understanding of basic physics and electrical/electronic principals should be able to pick it up quite quickly. What comes less quickly - and to some never - is the coordination between what you are hearing, what you want to hear, and what you need to do with your fingers to make up the difference! The only way to really get to grips with that is lots and lots of practice.
If you're interested in the principals and some of the various technical aspects of the job, have a look at:
http://www.rane.com/digi-dic.html
http://www.jblpro.com/catalog/suppor...=275&doctype=3
http://www.jblpro.com/catalog/suppor...=276&doctype=3
http://www.prosoundweb.com/ - especially the old forums
...for starters.
Also worth looking at the kit made by companies like:
Allen and Heath - desks and processing
AKG - mics
Audix - mics
Audio Technica - mics
BSS - processing and networked audio
Behringer - various
Beyer Dynamic - mics inc M88 (good for rock kick drums in conjunction with Shure Beta91), + radio mics and mic stands
Cadac (now in administration, very sadly...although may have been bought out by now) - consoles
Calrec - consoles
Camco - amplifiers
Canford - sells loads of stuff. prices not great unless on account.
Crown/Amcron - amplifiers
C-Audio - amplifier
D&B Audiotechnik - speakers and amplifiers
DBX - processing
Digico - consoles
HHB - pro-audio distributor
Klark Tecnik (last word spelt funny - not sure if that's right!) - processing
K&M - mic stands
L'Acoustics - speakers
Meyer Sound - active speakers
Midas - consoles
Sennhesier - radio mics and the brilliant (no bias
) HD25 headphones
Soundcraft - consoles
Shure - mics
Studer - consoles
XTA - processing
Yamaha Commercial/Pro Audio - desks and networked audio
Obviously there's loads of other players and Rane offers a fairly comprehensive list on their website.
Feel free to come back if you get a taste for it and want some suggestions of where to go for more info or work experience.
Chris