Writing a script for an interactive, animated, training program.?

Look up "storyboarding". You need to write storyboards to explain what appears on each screen (artwork/animation, text, prompts) and any visible or invisible interactive spots/controls/interface elements. Each storyboard should indicate what happens next after any user action. Think of this as a detailed instruction manual for anyone who might actually build/program such a thing. Of course, it also has to end up being an instructionally sound product. I'll ume for now you know something about adult learning theory, principles of instructional systems design, and human factors/user interface design.