You should visit the STAR Program up at the Smithsonian Astrophysical Observatory in Cambridge Massachusetts. They have activities for building small telescopes. Also, Project Astro which is run by the Astronomical Society of the Pacific has many class activities in astronomy. I am not certain this includes telescope making. It depends on how you want to go about such a project. Do you want to build a small telescope from commercially available parts, or do you want to grind and polish your own mirror? The latter activity as a class project will be logistically very complex, especially if you have never made a telescope from scratch yourself. It will easily take a full year of class time.