What Owism said. There's a mountain of info on that forum. That said, I self-studied cause I didn't see the need to spend money on a course that couldn't prepare me in the manner I could prepare myself (i.e. presentation, types of problems, methods for solving, etc.).
As for me, the resources I used to prep for the exam, and subsequently used for the exam, are:
NCEES practice exam
NEC
NESC
Graffeo
P. C. Sen Electric Machinery book (a hard book to follow and a bit of overkill for the level you're being tested on, due to it being heavily academic based, but does have some decent info)
Chapman (power systems and machinery - this one is a must have IMHO. I used this and Graffeo almost exclusively, outside of the codes)
Power electronics text from college
GA Tech binder I borrowed from a friend that took the course
You have to know yourself more than anything. You can have all the materials/courses at your disposal and still fail. You know yourself better than anyone else, so if you learn better in a classroom, take a course. If you're more motivated by self-study, then take that route. Most of all, know your references. I'm certain a large portion of those who fail on any given cycle do so due to inadequate familiarity with their references. And remember to breathe!! We have all sat in that testing center and know the feeling all too well!
Good luck!