Aspearin1:
To quote an old Clint Eastwood movie, "A man's got to know his limitations".
In other words, recall back when you were in school, and had to study for finals. Only you know your own study habits, and what worked (and what didn't work) when it came time for the big ones.
I took the EIT and PE exams back in the mid to late 1970's, so I'm sure format has changed on the new national exams. But since then, I've taken the Illinois Structural Exam (mid 1980's), and the California Civil Exam (mid 1990's). In both of those cases, the first step (as mentioned by many of the previous responders) was to get my hands on study guides and old practice exams relevant to the tests, and know them inside out. (You'd be surprised how often the same or similar test questions are asked over and over).
My biggest exam killer in school was not that I didn't know the material, but that I sometimes had the ability to freeze/panic if I saw a question where the answer or solution method didn't immediately pop out at me. So, as an added insurance policy, I bought some relaxation/self-hypnosis tapes to work on that aspect of my demeanor.
In summary, you know yourself the best, so trust yourself to prepare for the PE exam in the manner that you know best. Good luck!