I recently found out about Stump the Teacher, a blog by Josh Stumpenhorst, and the excellent collection of tutorial videos he has on the blog.
The videos are well done and easy to follow and understand. Topics include: Google Docs, Blogger, Greenscreen, Twitter, Evernote, and more.
These are great for people who want to get started with any of these tools, or even learn a few new things.
Definitely a resource to add to your list of great, on-demand, tech professional development sites.