if you want the Pilots Handbook of Aeronautical knowledge, go to the FAA website and download it for free. It's form AC 61-23C. I found it really helpful; but I've had it for a while and knew the stuff way before i even thought about the Marines or the ASTB. If you're going to take the test soon, I advise sticking to the Marine Study guide first and foremost, then the Arco book.
"Push the stick foward, the houses get bigger; pull back, the houses get smaller... unless you keep pulling back, then they get bigger again."