Took the Core Hardware exam yesterday. Passed with a 786 (586 needed to pass), I studied using Sybex, and Mike Myers Passport, plus looked at braindumps and took practice tests on the internet. Probably 80% of the questions i had, i had seen before on the practice tests. Studied for about 2 weeks.
The Sybex manual goes into pretty good detail, the mike myers is more of a quick overview, but everything is covered. Be careful with braindumps online, some of them have wrong answers.
Gook Luck