For me, it's
tape! I hate it when I reached out to my pocket and I can't find a piece of tape

. THere will be something that needs to be taped, either the foley bag, or the IV lines, anything! Oh yea...and also
scrubs that have lots of pockets, it will make your clinical easy as you can store lots of stuff so that you don't have to run in and out the room!
As for Books? I am using the new
HESI NCLEX RN REVIEW, it's the best nursing book that you can find because it highlights the major things that we need to know for the NCLEX or HESI.
THe
TABER MEDICAL DICTIONARY was a great help for me when I was taking Pathophysiology.
THe
DAVIS DRUG GUIDE was also a big help for me in Pharmacology.
I can't think of anything else, everybody has basically said everything