Inspired by this board, I did some research on the subject in various cookbooks and online. Here was my method, it is really simple...
Buy any amount of cod (I used 2 pounds), rinse and towel dry.
In a perforated pan, place 2 inches of kosher salt, then the cod, then cover with another inch of salt. Set pan over a drip tray to catch run-off, and set in fridge for 3 days. After 3 days, take cod out and scrape off salt, clean drip tray and perforated pan. (Everything was very moist at this point, and I was nervous it wasn't going to work). Pour 2 more inches of salt in the pan and repeat process for 3 more days.
At this point, the salt cod is done. It is not quite as stiff and dry as that bought in the store. According to sources, it should be used within 2 weeks, so not as stable either. Store wrapped in plastic wrap, then foil in the fridge.
Even though it isn't as stiff, it still needs 24-48 hours of soaking to reduce the salt content and soften the flesh.
With mine, I made a braised cabbage and canned tomato dish, and added the salt cod and sliced red potatos during the last 25 minutes of cooking.
It was delicious, and the salt cod was really nice.