I can just see it now, "Sir, no one on APC said I needed to study that"
I'm no expert, I've only taken 8 checkrides and signed up at least 20 different students, but if I were going to take a Practical Test...I may just start with a book called the Practical Test Standards. That's just me though. Other people like to guess what else may be asked.
I may even go over some FARs, a study guide or two, the POH, maybe a systems review, the AIM, Av WX services, and pretty much everything else I've ever learned as a pilot.