Excellent advice Andy - many thanks! I'll update the tut when I get a moment.
EDIT:
Seems I've just had a moment to update it
http://supercoldmilk.com/ac3dtut/beginner/can.html
EDIT2: I also added a top and bottom this time, and changed the method of drawing it a bit.
I'm finding that making tutorials demands a bit more thoroughness out of even something so simple and seemingly minor as a tin can.