I did a very quick wiki page on Administrator Functions. I realize this is really somewhere between user help and development. The value added might be in (1) explaining some of the features where its needed or helpful (I made a few NOTEs), and (2) linking out from that page to other more technical pages that are managed in ACP. Can't necessarily expect an Administrator to be a developer but also want to give them a heads up whats there and how its all connected.
Very rough still - If you would prefer different formatting let me know.