"There is no particular mystery in animation...it's really very simple, and like anything that is simple, it is about the hardest thing in the world to do."Bill Tytla at the walt Disney Studio, June 28, 1937.
Types
of Animation Control Systems
Principles
of Traditional Animation Applied to Computer Animation (John Lasseter, SIGGRAPH 87)
Tricks to Animating Characters with a Computer(John Lasseter, Course at SIGGRAPH 94)
Walking (Article from Digital Video, April 1997)
WWW Animation Book by Rick Parent, Ohio State
University