I passed the P.E. exam, but it took me (*cough*) attempts. I've figured out a few things about what works and what doesn't and thought I'd share that with you.
The P.E. exam is as much a test of your ability to take an exam as it is a test of your knowledge of the material. It's designed to get you to fail if you aren't paying attention. Some questions are gimmes, where you'll know the answer before you've even finished reading the question; others would take the better part of an hour if you approached it like a homework problem. Each of these is worth exactly the same value: 1 point. Your goal is to collect as many points as possible. It doesn't matter from which questions you get them; a pass is a pass.
I suggest four passes through the booklet:
The first pass should be all of the gimmes and questions that require minimal to no calculation; these should be solved in two minutes or less.
The second pass should be those problems that you know you can complete fairly quickly and definitively within six minutes or less. Between these two passes, you should have collected at least 50% of the points possible, leaving you with another 20% to 25% to go in order to be reasonably assured of a passing score.
Your third pass should be those problems that you're confident you can do (i.e. without having to spend a lot of time in your references), but that will probably take you longer than six minutes to finish. At this point you need to be very judicious about how much time you have left, how many problems you have left, and how you feel about the remaining problems.
Your fourth and final pass should be limited to those problems for which you will need to spend a non-trivial amount of time in your references and/or extensive calculations in order to solve. It's during this pass that you're going to start hearing your time warnings called.
REMEMBER: A score of 70% *may* get you a pass and a score of 75% will almost certainly get you a pass. This means you can afford to screw up as many as 10-12 questions on each half of the test and still pass the exam. If you run across a problem you just don't know how to deal with, skip it and write it off as one of those 10-12 questions (keep track of how many of these you have!); you're going to bubble in some kind of guess anyway and have a 25% chance of getting the point.
A few words about the time warnings:
"You have 15 minutes remaining...". You have time to finish the problem you're currently on and perhaps one more if you can choose the second problem carefully.
"You have five minutes remaining...". Finish the problem you're on and start looking for the bubbles you haven't yet filled in.
"You have one minute remaining...". At this point you're out of time to actually work any problem and need to just be filling in bubbles for every unanswered question. If you leave it blank, you've definitely missed the point; if you mark anything, statistically you have a 25% chance of getting the point. One chance in four is better than a guaranteed miss.
"Time is up, stop writing, pencils down." They're not kidding. You WILL be kicked out of the room and your test voided if you still have your pencil in your hand after this announcement, no matter what you're doing with it. You need to have all 40 bubbles filled in with some kind of answer BEFORE this announcement is made.
Regarding your references:
Don't bring in an entire damn bookshelf worth of references. Seriously, don't be 'that guy.' You're never going to have time to dig through all of those anyway and still pass the exam and it's just going to take up space and be that much more stuff you have to cart in and out of the exam room. It's not worth it.
For any problems that require calculations where one value is dependent upon the calculated value in the previous step (electrical circuits, power or refrigeration cycles, etc.), bring some templates with you with any conceivable value you might be asked to determine all worked out in terms of variables. Then during the exam, all you have to do is drop in the problem-specific quantities and "plug and chug" as my high school physics teacher would say.
Be very comfortable with US customary units and have a reliable unit conversion book with you, with which you are already familiar and comfortable before you get to the exam. I'll say no more on that point.
Definitely bring the Lindeburg "[Discipline] Engineering Reference Manual" if one exists for your field.
If you have a reference that you're likely to only need a few pages out of, consider photocopying those pages and getting them bound at Kinko's or Staples or something; are you really going to need the rest of the entire book?
If you have to pull a value off of a table, DON'T waste a bunch of time trying to interpolate between data points, either pick one of the two bracketing points or assume a value between them. The answer choices are rounded off for a reason....
.... on that note, you only need to work a problem as far as it takes to isolate one of the four answer choices. You definitely will never need to work it to the umpteenth place past the decimal.
If you forget every word I typed above, at least remember this: WATCH YOUR TIME. Time is the one asset you absolutely CANNOT waste. Once time is called, you're done. You should be CONSTANTLY aware throughout the entire four hours for each half where you are in terms of how many questions you've answered vs how many are still blank against how much time you have remaining.
Also, assume that the question is phrased in such a way as to try to trick you into thinking it wants one thing when it really wants something else, because I'm telling you, this happens. Pay very careful attention to exactly what quantity is really being asked for and make sure that you're only chasing that quantity. If you read a question and you're confused, read it again and a lot more slowly. If you think the test is trying to trick you, it probably is.
... of this take due notice, and govern yourselves accordingly.