Thinking animation? Think words on paper.
The most important part of any animation project is the script. You should always have a complete shooting script, with exact directions and highly specific detail, before a single frame of animation is done. Animators are the most highly paid specialists in the graphic industry, and you don't want to end up using them for a scratch pad. Expect many meetings, many discussions, a lot of thought and a number of revisions before you see a single frame of video.