Apple's iOS 5 Education Deployment Guide describes the options for large-scale iDevice deployment: infrastructure requirements, the Volume Purchase Program, configuration and management.

Volume Purchase Program is the 'Get Started' page for this program, which allows you to buy redeem codes for apps for 50% discount. The minimum quantity is Buy 10, get 20.

Apple Configurator is a tool that runs on a Mac that helps setup and deploy many iDevices at a time.