I started with 3/4" planed poplar boards from Home Depot.
I may try making a set of white ash paddles in the future, but I decided on poplar for my first set since it is inexpensive, readily available, and easy to work with.
Next I sliced one board into long strips 1 1/8" wide, leaving one 3/4" thick and planing the other to 1/2". I then glued the two together so I ended up with a board 1 1/8" square. This would become the shaft of the paddle.
The other I cut into a strip 2 1/2" inches wide for the paddle blades.
I then used Gorilla Glue to glue the pieces together in the general shape of a canoe paddle.
I cut the curve into the profile of the handle using a coffee can to draw and arc and the coping saw to do the actual cutting. I then used my Kershaw with a 3" locking blade to whittle the handle down even further before finishing it off with a belt sander and finally lots of hand sanding.
I used a jack plane to shave the paddle down to about 1/2" thick. I kept shaving until the paddle balanced perfectly with my hand where the shaft and blade come together.
The finished product. The shorter paddle is for my wife with a 30' handle. Mine uses a 36" handle.
REI has a good section on their website for determining proper paddle size.
I'll give an update once the weather warms up on how they perform.