When I took it, I studied solely from the testing materials I was given by Walgreens and passed it on my first attempt. I know that I got everything right on conversions, sig codes, dose volumes, etc.
I know that I missed some on compounding, hospital pharmacy procedures, cancer medications, and a few other things like that just because I had no experience with those and tended to study them less since I assumed they were less important to me in retail pharmacy.
So be sure to remember that the test will cover all aspects of it, even if the job you're currently in doesn't.