Any books for an it adminstrator/support?

I want to buy a few books to read to brush up on my knowledge of IT adminstration/support skills. Topics about user accounts, setting up networks etc.

I was wondering if anyone here could help me as im sure someone else has read a book that has these sort of things on, anything that you can recommend would be great.

Id prefer a book rather than just an online guide (if you dont mind), hope you can help.