"In a society that is increasingly homogenized . . . Southern Appalachia remains a refreshingly different place," writes author Jeff Bradley, a native who has roamed its back roads much of his life. He proves both an interesting and helpful guide to an area he obviously knows well and loves.

A writing teacher at Harvard University, Bradley leads the reader on a very personal tour of the four-state Smoky Mountains region -- eastern Tennessee, northern Georgia, western North Carolina and southwestern Virginia -- where, he says, "the old ways persist." In some places, farmers still plow with mules and horses, because they are more practical than tractors on the steep hillsides, and "the mountain speech is laced with words and expressions that the translators of the King James Bible would find familiar."

Bradley divides the Smokies into nine geographical sections -- including Great Smoky Mountains National Park -- each introduced with a nicely written essay that explores the local history and culture. "Places like Saltville, Va. and Kingsport and Chattanooga, Tenn. may be more interesting," he says, "when you know that in colonial days salt from Saltville was shipped from King's Port to Chattanooga."

In sections titled "Once You're There," he describes the sights, both scenic and historical, and points out special places to stay and to eat. In Jonesborough, Tenn., the Widow Brown's, occupying a Victorian home, serves "potatoes baked in pine resin, homemade whole-wheat bread and a mysterious nonalcoholic punch called the Parson's Brew."

This is an excellent book for planning a Smokies trip and for carrying along while you explore the region's wandering country roads.

* "Lodgings for Le$$." Rand McNally. $4.95 paperback.

This three-book series, a Mobile Travel Guide publication, features hotels, motels and inns in the United States charging (in the 1985 edition) less than $37.50 a night for two people. The guides, about 235 pages each, are divided regionally: the Northeast and the Midwest in one book, and the South and the West in separate books.

According to the series editors, the selected establishments are inspected annually to determine if they are "clean, well-maintained and well-managed." Each receives a rating of from one to three stars. Three stars represent "a truly excellent lodging experience," not easy to find at $37.50 these days. Places that represent "an unusually good value" get a checkmark in front of the stars.

The lodgings, as might be expected, tend toward budget-priced chain motels, but a number of distinctive accommodations can also be found. Among them is Breaks Motor Lodge at Breaks Interstate Park in the southwestern Virginia mountains. The lodge, fully deserving its two-star (and a check) rating, sits on the very edge of what is often called the "Grand Canyon of the East," where the views are superb.

In the big cities, the lodging choices are somewhat limited; and in some heavily visited tourist areas -- Colonial Williamsburg, for example -- listings somewhat above $37.50 are included. Nevertheless, these are handy guides for travelers trying to beat the high cost of rooms on the road.

* "Eurail Guide: How to Travel Europe and All the World by Train," by Kathryn Saltzman Turpin and Marvin L. Saltzman. Eurail Guide Annual. 816 pp. $10.95 paperback.

This reference for rail travelers is now in its 15th edition (1985), providing a wide range of useful information about train schedules, fares and special-rate passes in 115 countries. As the title suggests, however, the emphasis is on Europe, where there are more than 100,000 miles of rail lines (and that's just in the 16 countries honoring the Eurailpass).

The book is not specifically a rail timetable, but it does include arrival and departure times for 700 train journeys in Europe (most frequently taken by tourists) and more than 9,000 for the world. Among them are one-day round-trip excursions from major cities and a selection of the world's most scenic train rides, more than 50 in the Swiss Alps alone.

For first-timers, there's detailed information about obtaining a Eurailpass and ways to determine when such a pass is a good buy for you and when it isn't. Details on seat reservation policies in each country and categories of service available also are included. One chapter is devoted to "Europe's Greatest Trains," including France's high-speed Trains a Grande Vitesse.

Rail travel, say the authors, is "the least-expensive, safest, most-convenient, interesting and pleasant way to travel." Their enthusiasm shows in this remarkably complete guide.

* "American Southwest." Insight Guides. 305 pp. $14.95 paperback.

How to define the Southwest? The authors of this attractive and lively guide have done it succinctly and charmingly:

"Wherever you stand in the Southwest there must be somewhere, on one horizon or another, the spirit-healing blue shape of mountains. And thus you have Arizona and New Mexico, a slice of southern Colorado, much of southern Utah, and part of Nevada."

One of the great strengths of the Insight Guides series is the, well, insightful historical and cultural backgrounding they provide. This book, for example, takes in-depth looks at the region's Indian tribes (Navajos, Hopis, Apaches) and Hispanics, the two cultures that give the Southwest "its special flavor."

There are also fine chapters on what to see -- the Grand Canyon, Indian country, the red rock cliff dwellings, Las Vegas -- and what to do -- hiking in Utah, golf in central Arizona, white-water rafting on the Colorado River.

The Southwest is a strange and magnificent land, and this book is an excellent guide to seeing and appreciating it.