Our school district has many iPads. We are wondering if a "master" Apple ID can be set up for configuing purposes (creating a standard starting point with certain apps for all devices) and if the teacher to whom it is assigned can then set up their own Apple ID (a second, functioning ID for the same device) for personal app downloads, email, calendar, etc while leaving the initial information intact. Basically, we don't want them to be able to change what the IT dept puts on the iPad.
The Apple Configurator app was designed for deploying large numbers of iOS devices within institutions like schools. The Apple Configurator documentation explains the three different supported configuration modes (Prepare, Supervise, or Assign), and a video introduction is also available. Based on the wording of your question, the either the Prepare or Supervise method will likely be the best choice.
In addition to Apple Configurator, you may consider something for over the air management, such as Apple's Profile Manager, or Airwatch.
From there you can deploy apps, and restrict installation, in-app purchasing and set content settings.