I found that the Kaplan subject books, supplemented with Khan Academy note
documents (especially for P/S), were completely adequate for content review. I briefly tried to use the Berkeley Review books, but their "overpreparation is best" philosophy didn't jive with me; the dense style of the books and the unreasonable difficulty of the practice questions honestly served to intimidate me and made studying more painful, but YMMV.
Once you're done with your initial content review, do all the questions in the UWorld QBank
with explanations. Fill in the gaps in your knowledge by reviewing the explanations on UW, re-reading relevant Kaplan sections, and watching Khan Academy videos. Once you're done with the UW QBank, do the MCAT Section Banks. These are super challenging, but they represent many of the more challenging passages/questions that you'll find on the actual MCAT.
Next, do several NS MCAT practice exams (strictly timed), starting with the free diagnostic. Review all of the questions and make sure that you know exactly why the right answers were right and why the wrong answers were wrong. Once you've done several NS exams and reviewed your answers, do the AAMC MCAT practice exams.
In another thread, you said you were getting low practice scores around 500 and plan on taking the MCAT in August. The most important thing you can do right now is to do a massive number of practice problems
and to thoroughly review your answers and try to reinforce areas in which you are weak.