There are different levels of certification. Level 1 end user certification does not require taking a class, though you do have to take the test, which is online, at an Apple authorized training center. The level 1 test is based entirely on Diana Weynand's FCP book. Memorize it. Level 2 end user certification requires taking a class at a training center, and level 1 and 2 trainer certification requires taking a training class where you take the test.
All the best,
Tom