Whether you fly frequently on business or only occasionally for pleasure, there's a pocket-size publication that can increase your comfort. It's the "Airline Seating Guide."

The guide contains drawings of the cabin layouts of aircraft flown by all major U.S. airlines, based on information supplied by the lines, and both the U.S. and overseas editions are updated quarterly. The latest domestic guide, published this month and available only by mail order, has more than 90 charts from 20 carriers; the international edition covers 80 aircraft configurations used by 25 foreign airlines. Both also identify any seats set aside for passengers in wheelchairs and indicate those lavatories with provisions for the handicapped.

Some airlines -- including American, United and TWA -- will, request when you're reserving your seat, show you a seating chart for the aircraft you'll be flying. But many airlines do not offer that option. And if you reserve by phone you also will not have a chance to compare seat locations and select those furthest from (or closest to) the galley or lavatory, or those nearest emergency exits (sometimes providing more space), nor will you be aware of those seats that have the most legroom or offer limited or no recline capability.

But with the "Airline Seating Guide," you need only ask what type of aircraft is scheduled for your flight, and the guide's seating chart for that plane will show you what choices you have and which seats offer what advantages. (Occasionally, of course, airlines need to designate a different aircraft shortly before takeoff, which could change the seating arrangement.)

Modern jets vary widely in seat layout -- and even the same type of plane can differ in interior arrangement because airlines modify configurations to suit their individual needs and seasonal demands. The intense competition spurred in recent years by deregulation and economic conditions has resulted in additional seats being installed, often further limiting leg and elbow room. About 25 percent of airline configurations change over a three-month period, according to the Carlson Publishing Co., which produces the guide.

"Business travelers are our most loyal contingent," says Cecelia Henderson, vice president of the publishing firm, especially "six-foot salesmen who are tired of folding themselves like paper clips in their seats."

The "Airline Seating Guide," U.S. edition, costs $29.95 postpaid for an annual subscription or $10 per copy; the overseas edition is $34.95 or $12 a copy. More information: Carlson Publishing Co., 3532 Katella Ave., Suite 223, P.O. Box 888, Los Alamitos, Calif. 90720.

BOY SCOUT MUSEUM: The new national museum of the Boy Scouts of America has opened on the campus of Murray State University at Murray, Ky., in the southwestern corner of the state.

Described as a high-tech combination of theaters, time tunnel, electronic games and other computer gadgetry, the $2.5 million museum is designed to convey to visitors the values at the heart of the 76-year-old scouting movement. The facility, housed in a 50,000-square-foot building that once was a student center at the university, replaces the former Johnston Historical Museum at North Brunswick, N.J., which closed in 1979 when the Boy Scouts moved its headquarters to Irving, Tex.

The $7 million collection of more than 30,000 items includes 54 of Norman Rockwell's original Scout paintings, 22 of which already are on display. The time tunnel leads back to the early 20th century and the founding of the BSA. Still incomplete, the museum will be open every day from 9 a.m. to 8 p.m., including weekends and holidays, through Sept. 30, when it will close for completion of renovations. It will reopen next spring.

Admission is $4.50 for adults, $3.50 for children 6 to 12. More information: The National Museum, Boy Scouts of America, Murray State University, Murray, Ky. 42071, (502-762-3383, 3190 or 3188.)

WILLIAMSBURG SENIOR TIME: Williamsburg, Jamestown and Yorktown -- Virginia's Historic Triangle -- have designated September as "Senior Time," a month of activities aimed at citizens visiting the area who are age 55 and above.

More than 80 businesses will offer discounts ranging from 20 percent to 50 percent at hotels, motels, private guest homes, attractions, restaurants, campgrounds and shops.

Each day there will be special events, including concerts, an arts and craft fair, a Scottish festival, lectures and "Publick Times and Fair Days" at Colonial Williamsburg. You can play at Busch Gardens, the Old Country; visit James River plantations; cruise inland waterways; retrace the steps of 17th-century settlers at Jamestown and see where George Washington's Continental Army triumphed over the British at Yorktown.

The Williamsburg Hotel/Motel Association can provide reservations at more than 65 hotels and motels; call (800) 446-9244 or, in Virginia, (800) 582-8977. It is necessary to ask for Senior Time rates when making reservations or purchases. More information: Williamsburg Area Tourism and Conference Bureau, P.O. Box GB, Williamsburg, Va. 23187, (804) 253-0192.

WOMEN'S ADVENTURE: Womantrek, a leading organizer of adventure trips for women only, will conduct a 14-day oar-powered rafting trip through the Grand Canyon beginning Sept. 15.

The 225-mile journey along the Colorado River includes both the challenge of roaring white water and quiet stretches when the rubber craft float silently below towering rock walls. Passengers will help paddle the boat, and each afternoon after camp is set up there will be time for swimming and short hikes. The guides are expert women rafters, and no previous experience is required of those signing up, according to Bonnie Bordas, director of Womantrek.

The National Park Service controls the number of people who travel on the Colorado by limiting the number of permits issued to the nearly two dozen concessionaires who operate river trips through the canyon. The purpose is to minimize ecological damage, which results primarily from the impact of camping, says a Park Service spokesman.

Land cost (excluding round-trip transportation to Flagstaff, Ariz.) is $1,450 per person, which includes food, rafting equipment, guides and permits, but not personal camping gear. A deposit of $300 to reserve space is due now -- minimum group size is 12. A similar 14-day trip has been scheduled for Sept. 14, 1987. More information about these and other adventures: Womantrek, 1411 E. Olive Way, P.O. Box 20643, Seattle, Wash. 98102, (206) 325-4772.