Because the media center is often where new hardware gets stored, the media specialist may be responsible for training teachers how to use it as well. You can do this in whole group sessions, but it is more likely that it will happen "just in time" when a teacher needs to use the lcd projector or wireless response system. For those times, it is helpful to have a simple description that shows the necessary hook ups or software windows. A digital camera can be helpful for providing pictures of connections or you can use screen capture software for pictures of software.
The media center often has software not available in other places, such as databases or online subscriptions. It is important that you introduce both students AND teachers to these resources.