The column is going to be about 32” long. To join the four sides it decided on using a rebate on one edge of each piece verse just butting the pieces together. Using this method, helps to hide the but end of each piece. The rebate is 3/4” x 1/2” which will leave a 1/4 “reveal.”
You can see in pic two that I cut the rebates a little wider than 3/4”. This way I can plane the edges down for a perfect no gap fit.
-- Chunk's Workshop pictures: http://spadfest.rcspads.com/thumbnails.php?album=135