I agree that tabbing your Engineering Reference Manual was essential. Another thing that helped me was to print out and tab the index of the MERM as well. That way you don't have to mess with the index in the 2 lb book. Practice problems and know your reference material as well.
Printing and tabbing the index of the MERM is a great idea - wish I would have thougth of it! I had every major section of the MERM tabbed, in addition to each section of the index, and the conversion tables I knew I'd be using. I also tabbed the morning and afternoon practice problems in the NCEES practice problems book.
I worked practice problems and studied mostly out of the MERM, since I knew I'd primarily be using it during the exam. I took about 12 references with me. Besides the MERM (which I used for probably 95% of the exam) I used my Thermodynamics (Cengel, Boles), Machine Design ("Mechanical Engineering Design," Shigley, et al.), and Mechanics of Materials (Gere) texts. I looked for something for just a minute or so in my Physics text (Serway, Beichner) but didn't have any luck and went back to the MERM. I also took my vibrations, fluid mechanics, heat transfer, statics and dynamics texts, in addition to the Machinery's Handbook (didn't touch) and Roark's (didn't touch). I also bound my study guide from the FE review course I took while in college and took it. I think I refered to it once or twice during the PE. Obviously I had more books than I needed, but they fit in a back pack and a book bag, so it wasn't a big deal.
I studied maybe 25 hours total, but really wish I had studied more, especially for the HVAC, economics, and some of the thermo questions. I knew going in that these three areas were my weak spots. I was glad to see only one economics question (maybe two... can't remember. In fact, it blows me away to hear people say they know the number of questions they got right, wrong or guessed on. I was way too caught up in working problems to keep track). The good news is that I passed. I've never had test anxiety, and that served me well on October 29th. Also, I recieved great study and test taking strategy advice from a co-worker.
During the morning portion of the exam, I would skip a problem if I knew I didn't know how to do it, or felt I could do it but would likely take longer than six minutes. I didn't read through the entire exam before answering - my philosophy is why read each question twice? If I could do it, I did it then. If not, I came back to it. I finished the morning portion with enough time to go back, work difficult problems, and check some work - just as my co-worker said would happen. In the afternoon, I skipped fewer problems, but not because I knew how to do them. I just decided to do all but the ones I didn't know how to, even if it took longer than six minutes. I finished with enough time to work a few I skipped and make reasonable guesses on the 3 or 4 remaining.
I had a comfortable feeling going in to the exam, but part of it might have been trying not to be freaked out by the fact that I had only studied about 25 hours. Again, I've never had test anxiety. I felt good about the morning half of the test, but after the afternoon half, I felt like I had no idea if I passed or failed. I knew I hadn't just had my ass handed to me, but I was worried that stupid mistakes and unlucky guesses would spell doom. Needless to say, I was wobbly for a while when I found out I passed.
Hope this helps, because I know the advice I received definitely helped me. I attribute passing the exam with 25 hours of studying to the great advice I received and my lack of test anxiety, not because I'm better than anyone else. I'm thinking luck was a big part of it, too. I learned the MERM well, had it tabbed, and knew pretty much where to find most things in the MERM. The practice problems I worked got me back into the "homework" type of problmes and avoiding all the silly little mistakes, like fouling up units.