First things first...

First of all, I have to read A LOT !
Animation is a huge world and there're so many books... Many websites advice to get fundamentals with those books :

The Illusion of Life - Franck THOMAS and Ollie JOHNSTON
The ASK (Animation Survival Kit) - Richard WILLIAMS
Anamie - Simplify drawing for planning animation - Wayne GILBERT



The great lesson I learned from now on is, every animation has to be planned, organized with research and video references. Before starting on computer, drawing small thumbnails allows to figure out what's exactly on mind. So I start drawing (from zero too...). Here too some books are good to have :

Force - Dynamic life drawing for animators - Mike MATESSI
Facial expressions - Mark SIMON
and others...

So here I am writting, reading and drawing all day long...