Now the PCAT is a subject based test. With that said its imperative that you have been exposed the material before you begin. There is no way to do well with out being able to a least recognize the material.
Now if you go to your local bookstore or on line you'll find ample supply of books. Stick to Kaplan for in depth reviews of material as well as exams. Barron's books are easier than the pcat questions itself so stay away from Barron's review. Kaplan is somwhat overkill for the exam in my opinion. For the math, review old books (ie, calc book, ) practice how to find the answer using shortcuts, because it is difficult to solve all the problems the long way. So try plugging in answers or cues to determine approximate answers to locate a possible match. The biggest thing is review your basics. Basic Chem, OCHem, Math, etc. Its not as bad as it seems, just make sure you prepare properly. Most average about 50 being a science major with out review. So just relax and practice the test under timed conditions because time the limiting factor. Alright good luck remember that above 85 percent is considered to be "competitive"