<< I meant something online and free >>
Don't be a cheap ass. That test costs $80. $20-$30 spent on study aides is nothing.
If you have lots of time to study and you don't feel at all confident about your calc skills, I'd say get the Barrons *and* the Princeton Review study guides (more practice problems). If you've got the basics down, just get one then; they're both pretty good. They have very simple explanations that you can follow along. I only took Calculus AB, and with the help of the Princeton Review study guide (my calc teacher flat out refused to help me, that bitch), I was able to learn the additional BC topics well enough to get a 5.