I like the Kaplan book. It's more in depth than what you'll see on the PCAT but it's a great comprehensive review. Barron's and Peterson's are a little too easy and some Peterson's questions are frankly strange. I also liked the pcatprofessor for quizzing myself. Focus on the basics and try to know the general stuff well rather than spend too much time on small details that probably won't be tested.
Organization is the key. Catagorize the subjects into "units" so that you can see the progress you are making. For example, spend one day on Algebra, one day on Calculus/Trig, one day on Statistics/Probability, one day on Cell Biology, one day on Endocrinology etc. I think you smell what I'm cookin'
Organize all of the sections you need to work on, set up a schedule for studying and stick to it. Figure out how you need to study in order to retail the most material and go with what works! Good luck!