Well, after 2 months of studying, I passed my core hardware exam with a 560. I read Exam Cram 2 A+ Second Edition by James Jones and Craig Landes. In my opinion, this book worked extremely well for the amount of time I had to study. The practice tests were comparable to the other ones I have found online and with other CDs from other books (Mike Meyers books especially). Also, the tech notes on this website were a great last-minute refresher.