Guiding questions to help you develop a device management plan that works for you.

Procedures:

Where will your device cart or your devices be housed in your classroom?
Who will distribute the devices in the morning/beginning of each period, you or your students? Who will collect the devices at the end of the day/period, you or your students?
Who will be responsible for charging the devices?
What will happen on days when you have a substitute?
How will you handle "free time". Students should be held accountable for work done, even if it's nothing more than playing a review game. My suggestion would be to show students how to take a screen shot and email it to you.
Will students be allowed to carry the devices around the room, or will they have to stay at their desks? If they can carry them around, how should they do this?

What will your consequences be for misusing the devices? Will you use a step system for multiple offenses? A tiered system for types of misuse?
Will you allow your students to email each other during class? During designated times? Remember that you will have their usernames and passwords so you can go behind and check them! Designated times for online communication fosters motivation and engagement and lead to increased achievement!