I'll second the Craig Fraser recommendation. I'm about to send off for his video and book. Also, Fraser does some little how-to columns on his website:
www.gotpaint.com
Try
www.coastairbrush.com for some books, maybe even some pointers (can't remember much about the site).
Also, see if there are any clubs for that kind of thing in your area (model kits, more so than airbrushing, I've never heard of an airbrushing club).
I love the info that I get from magazines. There are two with very similar names, and I don't know which it is I prefer, but I believe it's Air Brush Action. They have tons of cool information.
Oh yeah, and for the record, I can't airbrush for crap. Take what I say with a grain of salt, but I do know that those are some pretty good resources.