Depends how thick your patty, and how lean the meat. Thicker patties should be cooked with relatively less heat. Leaner meat cooks faster. I like to cook my hamburger at medium high heat.
Shape and season your hamburger outside the pan. When you shape your patty, shape it so it's slightly dished into the center. That way when it cooks and tightens up, it will cook itself flat rather than round.
"Regular" hamburger is 80/20. That is, 80% meat and 20% fat. Let's assume you're making your patty with "regular," and shaping quarter-pounders about 1/2" thick. Don't forget to use wet hands when your forming your patties. After they're formed, season each side with a few drops of Worcestershire, salt, pepper, and a bit of granulated garlic. If you put the Worcestershire on first, you can spread it around with your finger and it will hold the seasoning. If you put the Worcestershire on last, the seasoning will clump unevenly.
Once your patties are formed, preheat your skillet over a medium-high flame. If it's non-stick ([I,]and ideally, it should not be non-stick[/I]), add a few drops of regular vegetable oil to the hot pan. You don't need much, you're not trying to fry the hamburgers; you're prepping the pan so the meat will release when it's seared, and to facilitate the rendering process so more fat cooks off. Roll the pan to make sure the oil flows easily (that means the pan is hot). Then add the meat to the pan, and JUST LEAVE IT. Don't flatten it, don't move it around, don't do anything. JUST LEAVE IT ALONE. Got it?
After two minutes (exactly) shake the pan and see if the hamburger moves on it's own. If not, wait 30 seconds, and shake again. If, after another 30 seconds the burger won't move by shaking alone -- push the burger on it's side with the flat of your turner to release it. You don't want to slide your turner underneath unless the burger can slide -- or you might tear up a perfect crust. Turn, and cook the second side for 2 minutes.
If you want cheeseburgers, have the cheese and the bun ready so they can go on the burger as soon as it's turned. This will melt the cheese.
Using medium heat will take longer, cook the meat more evenly, but ultimately give you a harder crust. Your choice. Very lean meat, like ground sirloin, will cook to medium-well in the center within seconds of getting hot. Not only do you have to watch it like a hawk, it's less tasty than regular. Also, enough of the fat will render out of regular that the cooked burger doesn't carry much more fat than lean or extra lean. Furthermore, lean and extra-lean meat will deform more as it cooks; your patties will look more like meatballs. On the other hand, economy 70/30 will always stay a bit greasy unless cooked medium well or well.
Note: If you see drops of blood rising up to the surface of the uncooked side, you're looking at a hamburger which will be medium-well at least. If you see blood, turn immediately and cook the second side just until browned.