Do your students have access to iPads? Here are the best FREE apps for sketchnotes, and one that isn't free but is pretty great. If you are thinking about getting serious with sketchnotes then I would recommend Procreate, it is what I use.
Because beautiful tools make beautiful drawings, we endlessly refined Sketches brushes to create the most realistic drawing tools. Sketches school is a special edition of Sketches targeted for a younger audience, with a specifically designed interface making it very accessible to kids.