Here's a whole bunch of recipes. They all seem to use the same ingredients with few variations. I've never made one (I've eaten a few) but it seems pretty fool proof.
I love the one that is on the back of the Mrs. Dell's hash brown package. It is so creamy and yummy. I don't do the cornflake topping though, I just brown the cheese a bit and it is really gooey and yummy and bad for you. I had some green chile sour cream dip once that I used in place of the regular sour cream and it was delicious also.