One of the people I follow on Twitter is Jen Carey. She also has an Internet page called "Indiana Jen" which goes through a number of her assignments. What I like about this post is that it goes through into detail how students can create their projects. It even includes a way for students to know if a webpage they are using is a good one as well as the fact that kids need to write out their script before recording their screencast.
Above is an example of one of her students' work.