Hey Jason,
Yeah, I got bit by the acting bug around 15. By the time I graduated high school I'd done a dozen shows (can't believe I had that much energy!)
As for software, Audacity is free and not bad. I use Sound Forge (from Sony). They have a $70 version I believe that handles a lot... Also use Magix Audio Cleaning Lab - pretty good at around $40.
One book? I'd have to go with "Word of Mouth" - check out the reviews section for more books and reviews (department of redundancy department chair).
Someday we'll have to have an Animal Showdown...
Joe J Thomas
www.JoeActor.com