from my experience, you do need at least one (better two) good prep books beside the PMBoK Guide.
Which one depends on your learning style and preference.
Rita's, of course, is still the most popular one and it is one of the best for sure. But it can be overwhelming.
I do also like HEADFIRST by O'Reilly or also the one by Joseph Philips. A very comprehensive one is the one by Scott Payne for instance.
Since we are not allowed to post external links here at the discussion board, I will send you a private message also.