1/2 pound of ground Certified Angus sirloin hamburger for each person you're expecting to serve
Charcoal brickettes - don't use the self-lighting kind
Wood Chips (oak, maple, mesquite, hickory, etc)
Outdoor Grill with hood
Three good web sites that talk about the grading of beef in the US:
Buy the best hamburger you can afford. However, the leanest hamburger is not always the best - I prefer ground sirloin, which is not the leanest, but has just the right amount of fat content for a very good burger. Make sure it has been ground the same day you're purchasing it.
Once you're home you'll need to light the grill. To do this, first place enough charcoal in your grill to provide a bed of coals large enough so that you can fit all of your meat above the coals without any being above a spot that won't have coals under it.
Take the wire grill and scrub it to get the old stuff off of it. You don't have to be a perfectionist about this, since the grill will become sanitized from the heat. Just get all the rust and fleks of old grease and stuff off of it. Put enough lighter fluid over all the coals to lightly cover them - don't use too much. Then light the coals, place the grill on top, and go inside to prepare the meat.
Wash your hands very well.
Then put the hamburger in a bowl and begin to knead it with your hands. Squeeze the hamburger so it comes out between your fingers. What you are trying to do is to break down the meat so that it becomes "mushy" instead of lumpy like it is when you buy it. This "mushiness" is what makes the hamburger stick together well instead of falling apart on the grill or plate.
Form the hamburger into patties about 1/2 to 1 inch thick, and about 4 to 6 inches in diameter. Make sure the edges of the patties are smooth and no pieces of hamburger are sticking out.
Wait until the coals have all pretty much turned grey before adding the meat to the grill. If your grill has an adjustable height, put it so that the grill is about one inch above the coals to start out. The idea is to sear the outside of the hamburger, thus trapping the juices in the middle. Don't go away at this point - keep an eye on it, because with the meat so close to the flame it is easy for it to burn. This first part of the grilling should only take a couple of minutes.
Once the bottom of the patties are nicely browned, flip them over and let them get seared on the other side, too. Again, just a couple of minutes is all it takes, and keep an eye on them so they don't get burned.
Once the hamburgers have been sufficiently seared on both sides, flip them over again and immediately increase the height of the grill so that the coals are as far from the meat as you can get them. If your grill doesn't have an adjustable lever, place the meat on the outer part of the grill where it is not directly above the coals.
Put a few wood chips on the coals, and make sure they catch flame. Then close the lid and adjust the vents to produce the maximum amount of smoke. Let the meat smoke for about 5 minutes or so, after which it's ready to serve!
I don't put any flavorings or additives to my meat - the smoke will be more than adequate to illicit ooohs and aaahs from your admiring eaters!