The website http://animatedknots.com/index.php has a number of videos demonstrating how to tie various knots. The videos/animations are very clear and allow you to follow along with each step or animate the entire process (with options for slow or fast). In addition to numerous scout knots, the site has categories for boating, climbing, rescue, fishing, household, decorative knots (such as the monkey fist), and whipping and splicing. This site could be very useful for teaching knots.