Top of the Line Material

This is an expensive program, but if you really want to see and master all the science of how the mouth moves, there is probably nothing better:

http://www.primalpictures.com/speech_language_pathology.aspx

On the other hand, you could start with this for FREE, and it is pretty awesome too, especially for the comparison's between English and Spanish:

http://www.uiowa.edu/~acadtech/phonetics/

Thoth