Cod is a nice fish to me. I prepare it quite simply: some white flour on a plate, add some salt, garlic powder, and other spices to taste, but you don't want it too strong. I get cod loin from a fishmongers or my supermarket fish counter - relatively cheap and ready to cook. Wash the loin under the tap and pat it dry. Just as is, gently place the fish in the plate of flour and coat it with a layer of it. Melt some butter - I use Lurpak which is a mixture of butter and margerine and is very tasty - in a frying pan, and place the fish in. Spatula the fish over a couple of times until the flour coating is a nice golden brown. Then eat. It'll work for all white fish, this.
Once I ran out of pepper and added some cinnamon to the flour by mistake. It made the fish so wonderfully tasty I add it to the coating all the time. ^^
An important note is if you find a small thin pink worm on the fish while you're washing it, DO NOT PANIC, it doesn't mean the fish is bad; it's a perfectly normal part of the fish's diet and life, it doesn't carry any disease we can get and it will not hurt you, just throw the little bugger out and give the fish another wash. Bad fish is a nasty colour and smells awful - it should smell like fresh fish, not unpleasant fish. My housemate's brother is a chef and he gave me that info, backed by by both our mothers who are domestic goddesses.