I've never taught a class on homebrewing, but I am a teacher. So, I would approach it the same way I would approach any lessons. Break it down. Start with the baslcs. First teach the basic ingredients, and then the basic processes, beginning with extract and progressing to all-grain. If you have time, you could then get into advanced topics such as recipe formulation, measurement and evalutation, then water chemistry. The topic, as everyone here on the forum knows, is endlessly fascinating.
There are a plethora of resources online, including dvds and youtube videos that you could use to supplement your instruction. If I were to assign one book it would be Joy of Homebrewing by Charlie Papazian. It is plainly written and therefore accessable to every one, and it breaks everything down into the basics, as per the above topics. The first forty pages can get your students through their first beer.
Take your time and enjoy it, and your students will as well. Good luck!