If your using a Microsoft backend you could try something like DotNetNuke, you just install it and manage the content yourself, pretty straightforward and I’m certain mr IT will more than capable of getting it up and running. Its open source so I wouldn’t recomend it for an internet site, but its fine as an intranet.
The latest version of DotNetNuke doesnt require a SQL server installation either, it will run from an attached database instance that should run as part of the standard configuration.
I’ve not had a great deal to do with Sharepoint but from what I remember sharepoint has “discussion lists” and “Discussion Database” features (i.e. the sharepoint version of a forum) but they’re poor at best and would certainly dissapoint users with their lack of functionality.