This podcast is a very good comprehensive explanation of what exactly it is that a sound operator does. Have a listen:
As previously mentioned we use an Allen & Heath iLive system int he auditorium. The control surface we have is the T112, which is connected to an iDR-48 Mix Rack. Please view the training videos below to learn how to operate the iLive System as the operator needs to know the ins and outs of the board
Here are more training videos to help expand on how to mix live shows: