Some help for the “new guy”

Like many of you out there I am basically self taught. I am a systems/network administrator for a branch of a very large company. The home office will help us out of any major jam, as well as advise on little ones. Anyway this was never my intended field but I find myself drawn into it and very interested in making it my career. I need to play some catch up, and would appreciate it if anyone could help me with good books that will aid in the learning process. Too basic is okay, I can always skip the stuff I already know, but I do feel I need a refresher. Thanks in advance.