Call center features?

I am very new to asterisk and would like to know if there is any add-ons, commercial or otherwise, that provide queue management and call center features in some sort of GUI.

Hi There are many. Queuemetrics do one. There is a stats package (I do a wallboard app that uses the data) from the same person who does flash Ops panel, Obviously flash ops has queue control. and lets you drag and drop agents to queues. So it depends on budget and what you want to do.