On his C0DE517E blog, Angelo Pesce has posted a fun slide deck for an introduction to a computer graphics class to teach how a GPU works. As he says, it's not a particularly great tutorial as there are no presenter's notes, but the scheme could be used to teach something similar.
He provides copies in PPTX and PDF form, which you can get here:
[attachment=35884:Where do GPUs come from.pdf]
