Our friend Monty Montgomery (creator of the Vorbis audio codec used in WebM) has started a video series about digital media. The first episode is an excellent overview of "the technical foundations of modern digital media."
You can stream WebM versions of the video in your favorite WebM-enabled browser or download it to your desktop and watch it one of many WebM-enabled media players. Supported browsers and players are listed on our site.
There's also a companion Wiki.