Your region service center will have a class or two (it doesn't require more than that), and then you just take the test. It's an endorsement, not an actual certificate, so it's really fairly easy.
I studied the guide available online with a few friends the night before the test, and we all passed. Of course, we were all seasoned teachers, and to us, our experience paralleled the information that was tested.
"If you have told a child a thousand times, and he still does not understand, it is not the child who is the slow learner..." ~ Walter Barbie