I know you didn't ask me, but I will add imput anyway
I used the official CRNE prep guide. it is pretty much the perfect prep guide. Some of the questions on the exam wore ALMOST word for word the same question...but twisted slightly so the answer would be different.
It will give you a 100% accurate look at what the test will look like, and how hard the questions are.
If I could give you any hint, it would be to study and know the questions in that book. Furthermore, study more on the subject of each question. The book not only gives you an idea of what the question look like, but it helps you know what topics they will ask you about.
I wish I could help in more detail...but I'm fearful of the confidentiality contract we sign