Blendshape Maya Tutorials

Blendshapes:

Corrective Shapes (Positive/Negative) - http://kay-dean.blogspot.com/2011/05/maya-tutorial-blendshapes-corrective.html

Operation Order - http://kay-dean.blogspot.com/2011/05/maya-tutorial-operation-order.html

Mirroring - http://kay-dean.blogspot.com/2011/05/maya-tutorial-blendshapes-mirroring.html