Need to dive into networking.

I recently changed from my old job into a position where I’m not very familiar with, Networking & Telecommunications. My main duties are still with computer hardware/software support issues, but in this new office I have also been assigned to support the telephone service & LAN (including Wi-Fi).
The college here in town doesn’t offer any courses that will help me on my quest for higher learning (really small town in Mexico). I want to see if anybody has some feedback on what books I should go & purchase, I don’t want to be the world’s leading expert in Telephone & Networking, but I really need someone to help point me in the right direction.