I had the exact same questions as you! I was very confused as to how to tackle all of the content needed to prepare for the exam! I used the Saunders Comprehensive NCLEX Review book which is awesome! I have heard that Kaplan is great as well. I think that no matter what book you choose to use, be consistent in your studies! Set aside a certain amount of time each day devoted solely to studying! I made a detailed schedule of what sections I would do each day and stuck to it. This ensures that you will have completed all you need to by the time your exam comes so that you aren't left cramming at the last minute!
After reviewing content in the Kaplan or Saunders book, you need to do questions, questions, and more questions! You obtained the knowledge from the books but then you need to make sure you can apply it through questions! I did some of the questions on the CD that came with the book but I mainly used: Mosby's Review Cards for the NCLEX-RN Examination (there are over 1200 with answers and rationales). Also, I STRONGLY suggest you get a book titled: Prioritization, Delegation, and Assignment by Linda A. LaCharity! This book focuses on questions like: what patient to assess first, what patients an LPN or CNA can have, what patients a new nurse, float nurse or travel nurse should be assigned to, who to delegate to and how, and how to prioritize a list of four patients based on their conditions! This book was my saving grace! You NEED to know how to answer those types of questions. The book was around $20. Also, make sure you know infection control forwards and backwards! Good luck with studying! The exam is not as hard as you think...i passed with 75 questions on my first try!