People often ask me what they need to know in order to "work at Pixar", or otherwise enter the animation or visual effects (or video game cinematics) field. The best training is on-the-job training (or internships). To prepare for jobs and internships, there are nowadays a number of great academic programs like the technical programs at Texas A&M or Carnegie-Mellon (or a number of other schools), or the animation programs at CalArts or Sheridan.
However, this book that I contributed to is a good reference for anyone interested in the field. It covers nearly every aspect of the field with enough depth that you can figure out what areas you might be most interested in as a career and then go find in-depth material about that areas. Or, if you're already a professional, you can learn about some aspect of the field outside your current area of expertise.