1) Learning to Teach Through Video (Leeder, 2009)
This is a fantastic article to get you up to speed on some of the principles of teaching and learning through video. The most important sections (in my opinion) are the Pedagogical Context and the Principles of Multimedia Learning sections. There is also a bullet-point list based on the Principles that you need to take to heart. Simply put, these are best practices built from theory and based in research.
2) Best Practices for Online Video Tutorials in Academic Libraries (Bowles-Terry, Hensley, & Hinchliffe, 2010)
Even though the article was published in 2010, the best practices are general enough that they still hold up well today. You can jump to page 11 for the practical findings.
3) Nine Ways to Reduce Cognitive Load in Multimedia Learning (Mayer & Moreno, 2003)
This is the research article that is the source for much of Leeder's discussion in the Learning to Teach Through Video article. Leeder, in the #1 article above, did a great job summarizing this info, but if you are interested you should read this source. It's about how the mind/brain processes information in regards to learning new content.
As recommendations based on these principles, Mayer and Moreno suggest: