Where to start?

Where do i start. Ihave been working in my company now for about two years. My title is IT Field Rep, I work in a callcenter/collection enviroment and i have been reading and searching for a place to start. Most of my knowlege has come from handson, Setup and deploy 30 computers here 150 there, troubleshoot net work problems, build cables, swap out a hard drive, Load software, punch down phones, etc..
Where do i start? I want to learn and it seems to me that i can do better with a certification behind my name. Let me hear what you have to say..