Well, I have a lot of friends who are SEO whizzes and experts, but I didn't actually start getting into it myself until my father and I tried to set up a t-shirt company, which fell through because we simply didn't have a clue about how to do SEO for e-commerce sites, and the SEO companies we consulted with wanted to charge us ridiculously priced fees.
After that, I got into niche article writing and content writing for websites via oDesk, became burned out after several months of content-churning, and then downloaded a copy of Moz's "The Beginner's Guide To SEO" plus Dan Thies' SEOFS guide (the 2011 edition). Now, I'm consulting for an insurance company, working on some original content for a new blog I set up recently, and working on staying up to speed as much as possible on the latest trends and happenings in the wonderfully batshit-crazy world of SEO! =D