Tom,
I'm currently working on a set of mu tutorials for my users. The tutorials are targeted to users and not admins, but they may help your users with some of the basics. Once I get them completed, I'll be making them available to the community at no charge. In the mean time, I do have a set of user tutorials for a regular WP install that you may find helpful...not a lot of difference on the user-side. You can see them here:
http://www.georgetownprofessor.net/podblog/?page_id=47
Here is the draft list of what I'm planning to include in the new user tutorials for my mu site...I'm still developing the list so any suggestions for other topics are welcome and again, I will be making these available for free when complete:
http://kentuckyclassroom.org/?page_id=16
Once I get the new user tutorials complete, then I may tackle a set of tutorials for admins. The most difficult part for me is developing and organizing a logical outline of topics to cover so that I can keep the videos under 5-6 minutes each.
So, if anyone would like to start a list of topics for an mu admin, then maybe I (and some other volunteers?) could start tackling this over the next few months as a way to give back to the community. This list would need to be very detailed so the topics could be covered in videos no longer than 5-6 minutes; therefore, a topic like "Installing Mu" would need to be broken down into several logical steps...and maybe even sub-divided into sub-domain installs and sub-directory installs.
Steve