The two commonly used books to study for the PTCB exam are:
1) Mosby's Review for the PTCB Certification Examination by James J. Mizner
2) Delmar Learning's Pharmacy Technician Certification Exam Review by Patricia K. Anthony
These books are good reviews, EXCEPT they have A LOT of errors! So beware!!!!! There were a couple of miscalculation problems, grammatical and numbering mistakes, so you have to be very careful. My friend bought both books and he had to switch back and forth between the two to make sure the answers were correct because there were too many errors. Personally, I don't trust any review study aid that has errors in them.
Personally for me, I took a couple of pharmacology classes in college and a whole bunch of other bio classes so the test wasn't too bad for me, but I definitely needed the review. I studied using only 2 books:
1) Brody's Human Pharmacology (4th Edition) by Minneman and Wecker
2) Pocket Guide for Pharmacy Technicians by Jahangir Moini
These books of course don't have any practice exams, but you can just get practice exams from online. The first one is very detailed in term of mechanisms but it has really good explanation regarding to different classes of drugs. You might not like it because it is quite detailed, afterall it is a textbook.
The second one was the most helpful. It was very straight forward, it had all the calculations, abbreviations, laws, drug information, etc. It is really really good for studying the PTCB exam.