Wondering where to start? It looks like there is a faint blue gasket material that looks worn out where the leak is showing. Is this a gasket replacement or worse? Any help would be greatly appreciated. (sorry if its vague)http://img138.imageshack.us/img138/5093/sdc14753.jpg Thanks!

If you find there's coolant near the blue sealant, it most likely dripped down from the water pump just above. Feel around the bottom of the water pump while the engine is cool and see if your hand shows wet.

but coolant passes thru the timing cover.... can be leak from timing cover, or the bypass hose near the top/front of the engine, or thermostat housing. all common low volume leaks.... in addition to what was posted.

Steve, you didn't say what year your truck is, or how many miles.

I'd suspect the bearings in the water pump first. There's a weep hole on the front of the water pump, which is designed to start leaking when the water pump is starting to go.