For 3D animation,
Animation Mentor is an online school that's really good and fairly priced. The full course is roughly $15,000, while most schools costs more than twice that much.
For traditional animation, you don't really have much. If your focus is character animation, I suggest you just do a lot of figure drawing, with emphasis on line.
Drawing Force is a good book for going over the animator's approach to figure drawing.
Animators are also actors, so studying that art form is also a must. Dance class can also help you understand how a body moves.
Animators are also story tellers, so learning how to tell a story through your pictures is a good thing to study. While it's focus is comics,
Understanding Comics is one of the best books on sequential art.
As said above,
The Animator's Survival Kit , is a must own for any student animator.