I'm Norwegian, and I live in Norway.
Norwegian people are used to most kinds of food, they travel a lot.
American, Mexican, French, Italian, Mediterrainian cooking goes well,
You only have to be sure that they get good boiled potatoes with hot meals.
Of course they eat fish, but it should be very fresh, and not too much "tampered" with - a la Meuniere, au agratin or just poached with Hollandaise-sauce is fine. They like desserts, Jellies, custards, flan etc.
The hard part for an American may be breakfast - they need lots of bread - homemade whith bran, coarse milled wholewheat flour, sunflower seeds in it, they will have cheese end cold cuts and 3 kinds of pickled herring and smoked herring jam and bacon and eggs and boiled eggs and fruit and cereals for breakfast - not all at once, but to choose between. The bread is the most important part.
Don't bother about "norwegian meetballs in gravy" etc They don't expect that from an American anyway, and their wives probably make it better (most Americans don't make good gravy, from my experience). They will expect and appriciate good American cooking. They may eat pork and lamb a little more often than americans, not only beef.
If you need help later, you can e-mail me. Ingrid.Fossen@su-fi.sri.telemax.no

Oh - Norwegians don't eat crackers in soups.