Yeah, I know the public school system failed me

But actually, I need to retake the math placement test for my college since I didn't do to well when I first took it. So, I was wondering if you guys recommend anything that would do a pretty good refresh/relearn that would help with the test. I remember after taking the test that I should of done better but for whatever reason, I couldn't quite remember how to exactly solve the problems they had on it. It seemed like everything I studied for didn't show up on the test (cert test from hell was the feeling I had).
I really don't want to buy school, school books (yeah no kiddie hard covers, it'll just discourage me and I'll do something else) but needs to be fast enough to the point so it doesn't feel it's too dragged out. I'm not sure if it'll be best to do it via book or something else, thus the reason I'm asking you guys, to find out the most efficient way to go about this.