Beginning Robotics-- Where Should I Start? Answered

Hello, as you can tell from my profile, I have a passion for robots.  I'd like to have a career in developing artificial intelligence in particular, and I would like to start sharpening my skills now.  Unfortunately, I'm not sure where to start.

I was wondering if someone could give me an idea where to start out, as well as if someone could provide a link to a C compiler (preferably free).  Thank you very much for any help.