Ashish recently emailed us to point out a great step by step head modeling tutorial, by Carlos R. Bisquertt, done completely in Blender. It has been published by CGarena and can be found here.
The tutorial covers everything except modeling the ear. Carlos states he will create a separate tutorial on modeling the ear for the head. If you'd like to give the ear a go now, Jonathan Williamson posted a great ear modeling video at Blenderartists that might work well to get you started. Find the video in the first post here.