I bought the NCEES practice exam and worked through it about 5 times until I had a good understanding of all the concepts. Honestly I thought it did a good job of covering everything I ran into on the exam itself. For exam references I took in the MERM, Shigley's Mechanical Engineering Design, and a photocopy of my worked out practice problems. I tabbed the MERM and shigleys quite a bit. I think all in all I spent about 300 hours studying, spread out over 6 months. I studied a lot the week leading up to the exam.
I think the biggest thing I remember about the exam that you should be able to prepare for is to pay close attention to units. Also understanding exactly what the question is asking you to do.
That's very similar to my approach. I worked the NCEES practice exam around 5 times as well, in addition to doing all but the last two weeks of homework from the PPI prep course ( I attended every lecture ). If I had to do it again, I would have stretched my studying over 6 months.
I waited for the PPI course to begin to start studying and it's about a 3 month program that leads right up to the exam. I managed to squeeze somewhere around 250 hours of study time into those three months, and that was that
hard and very stressful. I wish the course ended two weeks before the exam, I regretted not doing the last two homework assignments in the test, but I believe the extra study on the NCEES practice exam saved me on the test.
I also picked up some different study material that was really helpful in breaking down the concepts to their basics, it was a book by Timothy Kennedy, called Mechanical PE review, machine design and materials. I ended up using that book during the exam a couple times and it saved me each time.
Know your references very well. If you study enough with the MERM, you should have a good feeling of the physical location of each subject in each chapter, and you should even strive to be familiar enough with each chapter that you can recall the images of the examples you are hoping to locate during the exam. This way you can rapidly flip through a chapter instead of going to the index and back if you know the example or formula is near by.
Take time to breath if you get hung up on a problem. I skipped around ten problems in the morning and afternoon, and once I answered everything I knew I could handle, I went back and filled the gaps. I probably got 8 of 10 right out of the ones I skipped earlier in the exam, just because my mind was less stressed about time and sometimes, solving the other problems you know how to solve can lead you to solving one you may have been stumped on earlier.
I circled my answers as I went, and triple checked the scan-tron when I was done to make sure it matched up. Yes, I did find a couple bubbles filled in wrong, these things happen when your brain is melting.
So work problems of all types as much as you can, study between 200 and 300 hours, work the NCEES practice exam multiple times (until you can ace it), take a prep course and do all their homework, attend all their lectures, rework their homework, then work the NCEES practice exam again. Tab your references, become very familiar with them, and you should be good to go.
Also, I took the week off work before the exam and reviewed and studied a ton. I made sure to relax the day before the exam and only tabbed my references and flipped through pages while watching a movie. I also stayed in a nearby hotel the night before.