Guidebooks are as essential to enjoyable travel as those sturdy walking shoes everyone cautions you to wear on sightseeing treks.

There are guidebooks to plan the trip before you go; compact guides to carry along for insight on what you are seeing; and books to read when you're back home wanting to know even more about where you've been.

Now the Washington area has a specialty bookstore, opened only two months ago, devoted entirely to travel guides, maps and foreign-language phrase books. It is Travel Books Unlimited at 4931 Cordell Ave. in Bethesda, open Monday through Saturday from 10 a.m. to 9 p.m.

"There are a lot of sophisticated travelers in this area who are interested in doing their own homework," says owner Rochelle Jaffe, a longtime Montgomery County resident with 10 years of experience in the scientific and technical book business here, who spotted a need for her new business.

In a brightly lit shop decorated with flags and travel posters, she is building an inventory of both the standard and the harder-to-find guides to the United States and the rest of the world. Seasoned travelers, she says, do their own research -- with guidebooks -- before approaching a travel agent to handle the chores of making reservations.

One goal -- which with a rare exception she has realized -- is to stock all the current titles of such popular series as Frommer, Fodor, Fielding, Fisher, Michelin (Green and Red), Baedeker, the Blue Guides, the American Express Pocket Guides and several others. She also carries all the books in the catalogue of the British Travel Bookshop in New York City.

And, she points out, "I even have a travel guide to Albania," waiting for the very rare visitor to that xenophobic nation in the Balkans. She also has a respectable collection of guides to other Eastern European countries and to Africa, often not easily found.

She has begun ordering local guides from small regional publishers in the United States and already offers a good selection of bed-and-breakfast and country inn guides.

Since the August opening, among the biggest sellers have been books on Italy. So much so that she has had to reorder the Blue Guide to Northern Italy, although recently one could count 63 other Italy-related titles on hand, from walking and art guides to Florence and Rome to Livy's "The Early History of Rome."

Another popular item is the menu guide to help traveling diners know what they are ordering. She recommends the pocket-sized "Marling Menu Masters" to Germany, Spain, France and Italy ($3.95 each).

Strangely, Jaffe is not a frequent traveler herself and has never been to Europe, although she would like to go some day. "I'm an armchair traveler," she explains. "I spend a good deal of time traveling through books."

Jaffe's shop is rapidly increasing the variety of its inventory, and she has room to add more shelves. She recently began a shelf on cruising guides for the upcoming winter season and is stocking new titles on skiing and adventure travel as well as business travel. She will special order books not on hand.

Travel Books Unlimited is about a five-minute walk north from the Bethesda Metro stop, between Old Georgetown Road and Wisconsin Avenue. A five-story municipal parking lot is directly across the street. And, appropriately, it's located in a neighborhood of several ethnic restaurants.

For more information: (301) 951-8533.

STRASBURG SPECIAL: An all-day autumn train excursion to Pennsylvania Dutch country is scheduled for next Saturday, sponsored by the Washington chapter of the National Railway Historical Society.

The trip departs Union Station in Washington at 7:40 a.m. and the New Carrollton Amtrak station at 7:52 a.m. for Lancaster, Pa. There, passengers will transfer to a steam train of the Strasburg Rail Road, with its old-fashioned cars heated by pot-bellied coal stoves, for the short trip to Strasburg, arriving at 12:30 p.m.

Shuttle buses will deliver passengers to a Pennsylvania Dutch restaurant for a family-style meal, and there will be time to explore the Strasburg Rail Road's collection of old steam trains and to tour the Railroad Museum of Pennsylvania in Strasburg.

The return trip departs Strasburg at 5:30 p.m., arriving in Washington at 10 p.m. Fare is $49 for adults and $45 for children, 5 to 11. Meals are extra.

For information: Arlington Hobby Crafters, 625 N. Glebe Rd., Arlington; Hobby Works Inc., Laurel Center Open Mall, Laurel; or (301) 292-6481, (703) 765-1628 and (703) 569-0366.