i know how to set up a shared folder for use on your network but for the accessing it from school part i think you need a server.
To share a folder:
Right click on the folder you want to share and click on "Sharing"
If sharing is not in the list click properties and click the sharing tab.
If it says something like "You have not set up the network setup wizard yet. click here to do so." or something like that, click the link it says.
after it is set up, right click ont he folder again and click sharing.
then check "Share this folder on the network"
I am doing this basicly from memory because i already set this up in my house so i can't try it again. im sure other people on this forum can correct my mistakes
The above is the same for printer sharing.
i just googled on how to set it up and here is what i got: