Just some ideas...
Rely on a web portal for everything related to school ensuring that the portal is compatible with safari.
Disable app store, iTunes, with a secure code on every iPad.
Apply parental control also in each of them
Apply a twice a year check on the devices to make sure that kids are not fooling around with them
Use a wireless gateway protected with a proxy to filter undesired content. Have a look at DansGuardian, great filtering tool with teens at home trying to get some porn or warez software

Identify Mac address of each device with each potential user.
iPad were not made for corporate use, so it is a bit hard to have a remote control over them. So instead, you can control the data accessed like a portal where they can get their emails, school works, etc...
My 2 cents!
VicoPad addict!