I found this tutorial:
http://video.google.ca/videoplay?docid=-297613529041280875&hl=en-CA
But I have to be doing something wrong. I can add the verts along side the mesh as the tutorial says 10min in. The problem I am having in the retopo tool keeps breaking outside of the mesh I am supposed to follow. As soon as it breaks I can not go back into the retopo tool. I have to delete everything and start over. As you can image this is driving me nuts!!! Can someone please help me figure out why the retopo tool keeps breaking.
I first noticed this when I tried to duplicate some geomatry and then could not get back in to the retopo tool.