I have been sitting on this for a while but I think it is worth publishing anyway…
Our colleagues in the US published a whitepaper on how to set up a XNA lab called “Implementation Strategies for Microsoft XNA Game Development in Academic Laboratory Environments”.
The white paper describes all aspects of the lab setup, from creation of OS images, to connection to the Xboxes, to assignment of creators club codes.
I hope you will find it interesting and useful.