It's been a long time since I had to take the NCLEX now (20 years!), but way back in the dark ages when I did I found that those of us who relaxed the night before at the hotel & didn't try to study that night passed while those that stressed out and tried study sessions in groups or tried to cram didn't pass.
So my first word of advise is this. You really either know the stuff by now or you won't at the last minute so DO relax the night before taking the exams. After all, every day you've been in nursing school has been preparing you to think the way you need to think, to pass nursing exams designed to prepare you for the NCLEX, and to give you the knowledge you need to pass it. You know a LOT more than you give yourself credit for already!
BUT-- many fellow students from my class also used NCLEX prep books and prep courses as well. Kaplan has been conducting NCLEX test prep since my school days at least and lots of nurses swear by them, so if you feel you need some more structured preparation that might make sense too.
NCLEX® Resources & Prep