As part of my summer internship at Khan Academy, I wrote a post for our Computer Science blog on our design guidelines for teaching programming talkthroughs.
It's a pretty extensive post that involves most of what I've learned about teaching over the past few years. The intuitions mostly arose from section leading for Computer Science intro classes in Stanford's excellent CS198 program. I've also learned a lot from analyzing the good and bad of current talkthroughs, and the Khan Academy content that I have made. The post will serve as an internal guide as we develop more content, as well as a great way to interact more with the teaching community. Check it out!