"How do stop after you start?" It's the question every would-be skier asks. Questions about clothing, equipment, transportation and etiquette pale in comparison.

Jim Thorne, the official ski initiator of Black Ski, Inc., tells would-be skiers: "The first time out you can't stop. You just turn your skis until they are heading uphill and since they can't go uphill they have to stop."

Thorne gave his advice to nearly 40 would-be skiers at the club's annual beginners' seminar, the second session of which will be Thursday at 3523 12th St. NE. It is open to the public.

The seminar follows the club's fall membership drive. "People join because they have friends who are turned on by skiing or by some of the other things we do," Thorne said.

Thorne's advice to would-be skiers:

Clothing: The most important article is long underwear. If you don't own it, borrow or buy it. You also need a turtleneck or similar shirt that warms your neck (do not use a long scarf; it can be dangerous on the lifts). Dungarees are adequate for the first day, but for a small investment you can buy waterproof warmup pants to wear over them. Wear a jacket in which you can move easily. Don't forget a hat that covers your ears, and warm gloves or mittens.

Equipment: Don't buy anything. You can rent it all, which gives you an opportunity to see if you like skiing and will ski often enough to make the investment worth the cost. Although you can rent equipment in town, and bring it with you, you might be better off renting at the area. If there is any problem, an adjustment can be made immediately. However, if you are going to arrive at the ski area after 10 a.m. or if you wear an unusual size, you might want to rent in town. Rental equipment often is picked over very early.

Safety: Make sure rented equipment is adjusted properly for you. Today's ski bindings are made to release the boot if you fall, but they don't work unless they are adjusted for your weight. Make sure, too, that your skis have safety straps to keep them from careening down the hill when they come off. They can be dangerous to other skiers.

If you are injured or see someone who is injured, get help. Ski patrollers wear rust jackets with big yellow crosses on the back. They are trained in advanced first aid. Any instructor on the hill, any lift operator or mountain maintenance worker will know how to find a ski patroller if you do not see one. It is a good idea to put a pair of crossed skis upright into the snow uphill of the injured skier to warn other skiers to slow down.

You can help prevent accidents by yielding the right of way to the downhill skier; look uphill when entering a trail from the side and check before you ski across any slope.

Lessons: Don't try skiing without them. Your friends cannot teach you to ski, and you can't pick it up on your own without the risk of injury. You can get good beginning instruction at any ski area. If you want to become the most proficient in the least time, invest in a ski week of lessons.

The ski lodge: All ski areas have services, usually at the base of the mountain. First you must buy a lift ticket to be allowed on the slopes and on the lifts. Ask for special rates for beginners. You rent your equipment -- skis, boots and poles -- in the ski rental shop and at the ski repair shop, you can have equipment repaired quickly.

Most ski lodges have a cafeteria and lockers.

Where to ski: The best place to ski is wherever your friends are going.But if you are setting out alone, try someplace close. Ski Liberty in Fairfield, Pa., is the closest beginner area to Washington. There are also ski areas in Virginia within easy driving distance. A call to any ski shop will give you snow conditions and driving directions.

Thorne, a retired police officer who has been skiing for 11 years, points out to would-be skiers that they need not feel like Johnnys-come-lately. The Black Ski racing team took first place in the Washington Ski International tournament last season with a brandnew skier on the team.