John Yerhot primarily a Ruby on Rails developer, has come out with a series of screencasts for Unix, Linux and Open Source Software users at FOSSCasts, something like Channel 10. Only, these videos are released as free and Open Source.
You can subscribe to the screencasts through RSS feeds for different formats, namely Ogg Theora and Quicktime videos. You can also get the screencasts directly in your iTunes.
Each of these videos is less than 10 minutes in playtime and covers open source software and tips and tricks in general. The screencasts have a weekly release and are released every Friday.
It would have been better if the site allowed playing the video as well. Right now, we need download the videos to play them. Otherwise, the screencasts are very helpful and are for both novices and experts.