I took the P.E. in April and am taking it again in October. The only restriction on reference material in my state was that no loose leaf paper could be used. You could bring any textbook you want. Guys were literally wheeling around suitcases full of books or two wheel dollys with boxes full of books stacked on them. Of course, if you don't know what you're doing all of the references in the world won't save you.
The NEC will only be useful if you decide to take the Power Systems section of the afternoon portion, and even then there were only two or three questions. According to the moderator of the Passing Zone forum I joined this time around, the October 2008 P.E. exam will use the 2005 NEC.
I took the textbooks that I was most comfortable using. There are several I use on the job quite frequently so I'm used to flipping through them. There is no point in taking a bunch of material you don't know anything about into the test. You are better off guessing on a few than spending 15 minutes flipping through textbooks to try to figure out how to do one problem. Besides the Camara reference book you already mentioned, I took a circuits book, a power systems book, a calculus book, and the NEC. I used the Camara book for 95% of all the questions and only dug out the others once or twice each.
Edit: As far as studying, all I can say is do a lot of it. I didn't do enough the first time which is why I have to go through it again now.
