What is the best way to learn latin roots/prefixes to help for SAT?

I am a junior and will be taking the SATs this year and alot of my prep books suggest looking at the roots to help get an idea of what a word means if you don't know what it is completely. Unfortunately, it is too late for me to take an AP english course where i would have over 200 of these to study so what is the best way to learn them. Is there a good book or website or what
?