I recently ran a lunch and learn about unit testing and test driven development. Could not find any amazing videos out there, so we went with these. Any better suggestions please let me know in the comments!
This one is more theory up to about 1 hour, then it gets hands on but with Java.: https://vimeo.com/user28557683/review/153480907/f38b042f2a
Hands on with .net and some great advice for writing good tests, but pretty low resolution: https://www.youtube.com/watch?v=dJUVNFxrK_4
If you have PluralSight, here are some good courses: