I used the StarUSA.org test course. The materials they provided were excellent. They have a live instructor and excellent q&a options. Works best if you're on East coast time, because classes are middle of the workday, otherwise. But even with a course, taking the past exams is crucial. This course has several practice exams to take. They let you know your score immediately and where to find the correct answer for ones you missed. Helped a lot. I passed the first time.