THE CAVEMAN who brought home a wooly mammoth steak had only two choices: eat it raw or throw it onto the fire and grill it. There were no other cooking methods -- no stewing, no poaching, no frying. Yet, this primitive manner of cooking still has great appeal on warm summer evenings, when the scent of sizzling meat juices and wood smoke is enough to trigger both hunger and anticipation.

The term grilling (or broiling) means to cook briefly over hot, dry, open heat. Though grilling has been used to cook foods since man discovered fire, today it is usually regarded as a summer ritual. While grilling appears simple, a perfectly cooked steak requires as much skill and care as any saute'ed or stewed meat.

Only naturally tender or tenderized meat should be cooked on a grill. Tough cuts become even tougher in the hot, dry heat. If the meat is more than two inches thick, it's better to cook it on a covered grill or rotisserie to cut down of loss of juices due to longer cooking times. Steaks, chops and poultry are good choices for grilling. Fish and shellfish do quite well, too, if treated properly.

The perfect barbecue grill can be as simple as a rack propped up on stones over a wood fire, or as fancy as a gas grill fitted with built-in thermometer and motorized rotisserie. When you buy a new grill, look for one constructed of heavy metal with a removable and adjustable grill rack, a separate fire bowl and sturdy legs. In covered grills, whether kettle or box-style, look for three or more dampers. These are the holes that may be opened or shut to change the air supply and therefore the fire's heat level.

Certain tools make grilling easier: an electric fire starter, a long-handled fork, tongs and a spatula, brushes for basting, a wire brush for cleaning the rack and skewers for shish kebabs. A motorized rotisserie for cooking whole chickens and roasts is handy if it can be attached to your grill.

It's also quite possible to grill steaks and chops indoors in the broiler of your oven or in a very hot skillet on top of the stove. Directions for using your broiler will be given in the owners' manual. However, when possible, broiling should be done with the oven door open or ajar. This releases the hot air from the oven so that the meat doesn't bake as it grills. Instead, only the direct heat of the burner cooks the meat. Restaurant broilers are made without doors for this reason.

A preheated broiler and broiling pan will ensure that meat sears immediately when it is placed in the oven. Stove-top grilling also requires preheating the pan so that the meat sears. In both cases the meat is oiled (the pans are not) so that it doesn't stick to the hot metal. Both methods have the disadvantage of smoking up the kitchen, so turn on the exhaust fan if you have one.

Several centuries ago, the Chinese discovered a method for making charcoal; man has struggled to light it ever since. Briquets are made of wood that has been compressed and superheated. This carbonized wood burns with a hotter, more even flame than natural wood.

Modern man has invented many ways to start his charcoal fire, most of which are inconsistently dependable. Liquid starters are made of flammable liquids, all related to kerosene, and are allowed to soak into the briquets before they are ignited. While these liquid starters work well, they require care in handling and can give a chemical taste to the food if it is placed over the fire before the starter burns off completely. Paraffin is used in the solid-type starters. It lights the briquets quickly without the danger of flare-ups and explosion. But it, too, may impart its flavor if the fire is not at the red-glow stage when the meat is put on the grill.

The easiest method of all may be the electric starter. To use it, briquets are piled under and around the heavy metal loop, and the starter is plugged in for 10 minutes. The metal loop turns red-hot and ignites the charcoal. The one drawback is that a nearby electrical outlet is required.

For those hearty souls who prefer to build a fire au natural, the "fire chimney" or "fire can" will produce a fast, sure fire. To make this chimney, remove the top and bottom from a No. 10 can and use an old-fashioned beer can opener (the kind that makes triangular holes) to punch a row of holes around the bottom edge. Set this in the center of the grill. Crumple two sheets of newspaper in the bottom, and fill the can with briquets. Light the paper and voila! your fire is on the way. The air drawn in through the holes along the bottom of the can fans the flame and lights all of the briquets. You should have perfect red-hot coals in 30 minutes. At this point, remove the can with long-handled tongs or pliers and spread the coals with a poker over the bottom of the grill.

The fire is ready when the briquets are all glowing red and you can only hold your hand over the fire at the level where the meat will sit for two or three seconds (count them: one thousand and one, etc.) before pulling away. The fire is ready for steak, chops and hamburgers. When the coals have begun to show a layer of gray ash over a still-bright red glow and your hand can tolerate the heat for only four seconds, the fire is at medium level, perfect for foods basted with barbecue sauce and for fish and shellfish. When the coals are completely covered in thick gray ash and your hand can remain over the coals for five seconds, the fire is ready for slow-cooking foods: very thick pieces of meat, roasts, shish kebabs with vegetables. Any long-cooking meats, such as split chickens, are best grilled over this cooler fire.

Whether grilling takes place outdoors on a grill or indoors under the broiler or on the stovetop, the cooking instructions remain the same. The meat is seared rapidly then cooked until done. In the case of steaks and chops, the heat remains high since the total cooking time is short. But for chicken, ribs and roasts, the temperature must be lowered so that the meat doesn't burn before the inside is done. Adjust the heat by raising the hood away from the heat; covering with the lid and adjusting the dampers on a kettle-type grill; or by spraying water on the coals, which is especially effective for flare-ups caused by dripping meat juices.

Marinades and sauces add flavor to grilled meats, as do smoking agents in the fire. There are two types of marinades: those used just to flavor and moisten the meat, and those used to tenderize tougher cuts.

The flavoring marinade is usually based on oil flavored with seasonings such as garlic, onion, salt, pepper and herbs. A tenderizing marinade is similar, but it also contains an acid (wine, fruit juice or vinegar). The acids break down the tough connective tissue, and usually need at ample time to work properly. A large cut may need to marinate several days to a week, while cubes for shish kebabs only require eight or 12 hours.

Barbecue sauces are brushed onto the surface of the meat only after it has been seared. Most barbecue sauces contain a high concentration of sugar which is responsible for the characteristic glaze that is the sign of perfectly barbecued meat. Meat is never marinated in the barbecue sauce since the high heat used to sear it would char the sauce, giving the meat a burned taste. When you plan to make barbecued ribs or chicken, marinate the meat overnight in an oil and herb marinade. To cook, sear the meat on both sides before brushing with barbecue sauce. Lower the heat by one of the methods discussed above. Brush on additional sauce as the meat cooks.

Smoking agents, such as hickory, also add flavor by creating a fragrant smoke that leaves a residue on the outside of the meat. Other alternatives, such as rosemary, thyme, bay leaf and fennel -- fresh sprigs or water-soaked dry leaves -- are more subtle than fragrant woods. A fresh apple branch, stripped of leaves and added to the fire, enhances grilled pork chops. Soak hickory chips in water for an hour to get the full benefit of their flavorful smoke.

Following are some guidelines for grilling and broiling different types of foods.

* Beef Steaks: For the best grilled steaks, buy prime or choice grade steaks only. The well-marbled meat will cook to a juicy finish. Steaks should be at least one inch thick if they are to be cooked rare. Bring your steaks to room temperature and brush them with oil. You will need 30 to 40 briquets burned to the red-glow stage. Sear the meat on one side and cook until beads of juice appear on the top of the steak. Flip it to cook the other side. When beads of juice rise to the surface again, your steak is rare. Continue cooking until the steaks are done to your taste. An additional three to four minutes' grilling will produce medium steaks. Five to six minutes of cooking will produce medium-well steaks. Less tender steaks need to cook a little longer. Test for doneness by pressing the steaks with a finger. Rare meat will feel soft and yielding, medium will lose most of the softness and feel springy, while well-done meat feels hard and has no spring.

* Hamburgers: Buy a good grade of ground beef or better yet grind your own from chuck. Thick patties grill best since they don't fall apart as easily as thin ones. Brush the hamburgers with oil and bring to room temperature. Cook as you would steak. Cooking time for hamburgers will depend on their thickness but will be considerably shorter than a steak of the same thickness. Season after cooking.

* Chicken: Chicken is especially succulent when marinated in oil and herbs overnight. Use a low heat (the coals are covered with thick gray ash) with 30 to 40 briquets. Sear both sides of each piece of chicken, then baste with either the marinade or a barbecue sauce. Turn frequently as you cook for about 40 minutes. Remember that the legs will take longer than the breast meat.

A whole chicken may be cooked in a covered grill if a drip pan is placed in the center of the coals so that flare-ups do not char the chicken. Cook for about one hour or until an instant reading thermometer reads 160 degrees. If the chicken is browning too much, close all dampers halfway.

* Fish and shellfish: A whole fish may be cooked over medium-hot coals (glowing red with a little gray ash) if it is brushed with oil. Cooking time is about 10 minutes per inch of thickness or until an instant reading thermometer reads 140 degrees. Clams and oysters may be grilled until they open.

* Fresh corn: To grill fresh-picked corn, remove the silk (leaving the husks attached at the stalk end), pull the husks back up over the ears and soak in ice water for 30 minutes to an hour. The husks will retain some of the water and steam the corn. Place the whole ear directly on the grill rack over a low fire and roast for 15 to 20 minutes, turning occasionally. BARBECUE SAUCE (Makes about 3 1/2 cups) 2 tablespoons oil 1 medium onion, finely minced 4 cloves garlic, mashed 1 cup water 1/3 cup vinegar 1/3 cup lemon juice 2 tablespoons soy sauce 1/2 cup brown sugar 1 cup chili sauce 1 teaspoon salt 1 tablespoon paprika 1 teaspoon hot pepper sauce 2 teaspoons fresh ground black pepper 2 teaspoons mustard 1/4 cup worcestershire sauce

Heat a 1-quart saucepan and add the oil. Cook the onion and garlic until soft and lightly browned. Add the remaining ingredients and bring to a boil. Lower the heat and simmer for 30 minutes. Adjust the taste to suit; more sugar or vinegar or more seasoning may be added. This sauce may be used to baste chicken, ribs, hamburgers and pork chops