There are certainly a lot of opinions about how to cook fish.

first, cleaning. no scaling, very simple:

http://www.youtube.com/watch?v=AZh6IMPvR_o&feature=related

You then cut off the head, if you want. I don't put the "stuff" into the water, as that contributes to pollution of the water, but prefer to leave out, away from camp, where it is easily found by birds.

A simple backcountry cooking process: wrap the fish in foil with a little oil/salt, perhaps wild onions. Place them on coals for 5 min a side or so.

My favorite is to throw them into a bag of cornmeal/salt, then fry in oil of choice. I prefer the crispiness over number 1.

To be honest, I'm about 10,000 fish past loving the taste, so I mainly catch and release these days.