This was the first step.
Check out the finished product here:    • Sail Canoe Maiden Voyage!  
The leeboard and rudder here:    • Building Leeboard & Rudder for the Sa...  

A couple of poles, a plastic drop cloth, and a few nuts and bolts. Who would have thought that you can buy canoe sails at your local hardware store? Stay tuned for a followup video when there's actually some wind!

Warning: most of this video is boring and a waste of your time. The first minute or two is the only helpful/interesting part.