TOPOLOGY‎ > ‎

Head

Head

The flow is the direction of loops.(pic)



Flows should follow muscle flow and bone structure.(pic)

Study anatomical charts of the muscles of the face. Further you should study other reference materials like wireframes. 
There are some wireframes kindly provided by Toontje. (by the way, if somebody has a rapidshare account, pm me, I have some references too, but can’t upload so they keep them for a long time).http://rapidshare.com/files/104172001/topology.7z.html