A+, CCNA, MCSE, more...practice exams
 

I recently heard about this site from a new co-worker. Brain Dump Central offers practice exams for many of the major tech tests, and from what I've heard, about 80% of the questions on the real test are almost identical to those given on the site. It might be a good thing to look into if you're about to take a certification test, or you're not sure if you know enough to take an exam without taking a class first.