I didn't prep. I was told one week in advance to show up on a saturday to take it. If you know math pretty well, a thing or two about basic aircraft instruments, and english, you should do alright. It is actually pretty hard to fail but I have met people who didnt pass, even with preparation. But very very few people have that problem. Also, if you dont get the best scores, you can retake it after a few months (I think 6).