A+ attempts to test your hands-on skills, and a lot of the exam leans on
remembering what you did to configure this or fix that. The "500 hours" spec
is a reflection of the old standard which was six months work experience in
the technology.
Having earned A+ eleven years ago, and taken every version of the exam
since, and seeing the form of that exam today, I'd pick up somebody's lab
manual and start working through it. Course Technology has a decent one, I
think Mike Meyers has one too. The idea is to gain hands-on experience with
Win 98, Win 2k, the command line, and all manner of hardware.
If you work in the hardware, the test is fairly easy. If you study from
books instead, it can be a lot harder. If you learn some multiple-choice
test strategies, it becomes real easy.
-John O