It involved using bones and some controls for eyebrows and jaw. and creating blend shapes to achieve a few emotions. The model I rigged is "Samuel" by Leah Apanowicz, found on Creative Crash at http://www.creativecrash.com/3d-model/samuel-free-3d-model
What I've learned:
Lots about skinning and weights due to the huge poly count on the model.
How to build a basic facial rig and model the blend shapes using the sculpt tools to enhance it.
How to link blend shapes to a GUI for ease of access.
How to link blend shapes to the jaw controller to create accurate skin stretching.
Next step is to find a lower res model and try again, this time rigging the entire body and a full range of emotions along with all the controllers I can think of.