I like to add that the principles of animation are the same no matter the medium (traditional, 3D, stop motion, etc.). A good staring point is to read the book The Animator Survival KIt, there is also a video version of the book http://www.theanimatorssurvivalkit.com/. I know people in the industry that were self taught, they learn by watching cartoons, books, videos. Learn animation in the medium that is easier for you. I recommend drawing because it train your eye and is cheaper.
Good luck!
