I took the exam Wednesday. Our class had to get 850 to graduate, and we all passed. We took the HESI review class and most of us purchased the HESI NCLEX-RN Review study manual with CD. The manual with CD was about $55 and a good investment. It covers all the basics. The CD has 5 or 6 practice exams with rationales.
It worked for us, but I think reviewing a decent NCLEX review book and going through as many questions (with rationales) as you can will prepare you.
About the exam itself: 160 questions that cover about everything.