Linux server with lots of students - assigning individual read / write for students in /var/www

I use (and love) linode for my web hosting, email, database, and other linux needs. I'll be using linode for my web applications class next year (about 15 students). I had a problem thinking how would I enable students to write to a web directory (var/www) without giving them all SUDO access (and allowing them to write into another students directory). 

This took me some time to find a solution, and it is beautifully simple (of course). Click here to see the thread. 

If you make /var/www writeable by its group and add the user to the group, that user will not have to use sudo. 

Try this: 

sudo adduser www-data 

sudo chown -R www-data:www-data /var/www 

sudo chmod -R g+rwX /var/www 

The user should then be able to edit /var/www/ files without hassle. The first line adds the user to the www-data group, the second line clears up any files with messed up ownership, and the third makes it so that all users who are members of the www-data group can read and write all files in /var/www. If you are logged in as you need to log out and log back in for the group membership to take effect. I confirm this works.