I found Barron's a great study tool to give you a good foundation for the PAT. The kaplan PAT is too easy imo, I found the Topscore PAT to be representative of the real thing, since I averaged around 23 on Topscore and got a 23 on the real thing.
Their cube counting strategy is great. Other than that, they give you a good foundation for the rest of the exam but I didnt really understand how to do TFE an keyholes until I bought Crack DAT PAT.
I bought mine on ebay for $10. If I answered a question I checked out to make sure if it was correctly answered. So I did study from that. Barron's can be lumped in with textbooks, topscore, kaplan, etc...but should not be the go to study guide
I'd like to add that probably the most useful thing you can do is just practice practice practice. Get your hands on as many tests or old tests as possible and expose yourself to as many PAT problems as possible and you'll do well.