Here are a few that I have that I have found really helpful.
Nursing Care Plans, Nursing Diagnosis and Intervention 5th edition
Gulanick and Meyers
published by Mosby
Fluids, Electrolytes and Acid-Base Balance
Prentice Hall Nursing
Reviews and Rationales
there is a whole series of these like med surg nursing/ob nursing and they are all great!
Lippincott's Review Series
I also went to my schools library checked out a bunch of NCLEX books, I practice the questions and return them. I also bought some of those NCLEX flascards for about 6$ with shipping off half.com...the older versions of the nclex books are cheaper and the questions are all still good practice!