I have come across this course, from grumoschool.com http://www.udemy.com/how-to-create-awesome-demo-videos/
But I find the package a bit steep and don't necessarily need to know all stages of the production. So for good reference I'd love a breakdown of learning resources and the tools most adequate for each of these stages:
Scriptwriting
Storyboarding
Voiceover recording
Animation
Video editing
The overall process and workflow for a demo video
Disclaimer: I don't if things such as video animation and tips on how to do the voiceover (as opposed to how to record it), as well as everything that draws on marketing skills, are on topic on this site.