Sean - I have seen a couple of installations at some private high schools. The staffing requirements depend on how you want Moodle used and how easy you want things to be for the students and teachers. On one extreme, I've seen someone setup a Moodle server
, create teacher accounts and give the teachers course creator rights and let them handle it from there where the user's sign up and register for courses that the teachers create. This requires very little staffing other than setting up a Linux server and installing Moodle. Honestly this could be done with someone with less than average technical skill in a day.
Providing support and having the knowledge of what to do if the database
gets corrupted, customizing things in Moodle to behave a particular way, etc. all takes a little more time and knowledge but not too much.
The other extreme was what I setup for a school with about 100+ teachers and 1000+ students. I wanted Moodle to be a turn key solution for them. I created all of the user accounts, all of the courses, uploaded all of the user images, enrolled students in all of the classes, etc. Learning how to do that for the schools particular Student Information System (SIS) took a significant amount of effort but I learned a lot in the process. The school had a few tech. folks on staff that were gracious to help out with resetting student passwords and things like that. It would be nice if there were a full time person to handle such an installation; however, life is seldom (if ever) ideal.
I hope this gives you some idea of what to expect. Let us know if you have more specific questions or concerns. Peace - Anthony