You can create a local user ID on laptops for access to the C drive only, fairly easily. Someone would have to either copy lesson plans to an agreed upon area of C, use a flash drive with the lesson plan on it, or email the lesson plan to the sub's personal account. With this method, the subs would not be able to see our network, but this would give them access to a laptop and the Internet.
How to Create a Personal Account for a Substitute
1. Go to the Control Panel, Administrative Tools, and Computer Mangement.
2. On the left side, Click on Local Users and Groups and choose Users.
3. Go up to the Action Menu at the top and choose New User.
4. Fill in the lines, including a password. Uncheck "User must change password at next logon" (unless you have a really long term sub) and put checks in "User cannot change password" and "Password never expires."
5. Click Create and Close.
6. I would not suggest trying to put the new sub user in the Administrator Group. They don't need that access.
7. To login, the sub would need to know the sub ID and password and would need to change the third line of the login screen from your school's domain to the other choice - which is called logging in to the local box (this computer only).