New Data Network Specialist Please Help

Hello,
I was recently hired as the Data Network Specialist. Much of my IT experience is in Help Desk which includes HW, SW, and telecommunications; with not much experience in configuring switches or managing LANs I have only watch the Network guys in my previous job and asked them some questions. Are there any books, websites or other such information that I can gather that will help me in my transition?

FYI: The switches are Black Diamond and Extreme Networks, but we may be going to a new vendor soon possible Foundry, but this is the first that I have heard of either.