There is a video series on ShowMeDo that has 8 episodes about svn.
It's somewhat out of date, but video are quite a good medium.
Making screencasts in linux is explained here:
Producing a video series that is hosted by Subversion would be a good project for a technical writer.
The outline of this would be:
1. prepare the script and co-ordinate contents with dev. (wiki is great here, so everyone can muck in)
2. create the props (files, commands, output, etc)
3. record the video
4. Produce/co-ordinate the recording the voice over.
Some video principles to consider:
a. Use as few words as possible, and keep the video short and to the point. Break up the lessons into 5 minute chunks, just perfect for a 'tea-break'.
b. No opinions, just the facts. Let the user think for themselves and find their own preference.
c. Type the commands, seeing the 'animation' makes it easier to remember.
d. Use dark background and a colorised bash.
e. Use good sound quality and find someone with a good, pleasant voice and easy accent with clear diction that can be understood internationally with ease.
f. Keep the contents timeless and in parts, so that the videos can be reworked easily.