I used this book: https://www.amazon.com/Practice-Problems-Manhattan-Strategy-Guides/dp/1941234518/ref=dp_ob_title_bk
I studied for about 6 hours total (was juggling applications and school at the same time) and did well enough that I can apply for any grad program I want to. Got 170 Q which is all I wanted, and did better than I expected in Verbal and Analytical
For the general GRE, I used a combination of Manhattan's 5 lb Book of Practice Problems and the ETS Official Guide. For the subject test, I used Princeton Review's Cracking the GRE. The 8th edition is slightly outdated in the psychopathology section (it still uses DSM-IV but we're on DSM-5 now), but otherwise is a very nice comprehensive review.
First test is free. For all 6 costs $40. Good luck! https://www.manhattanprep.com/gre/store/online-resources/gre-practice-tests/