Pillar of the Sky, by Cecelia Holland (Ballantine, $9.95). Cecelia Holland has built a marvelous tale around the creation of Stonehenge. How those massive pieces of rock came to be configured as they are is still a mystery, but Holland's story of a brilliant young outcast, and how he transformed a vision into the reality of Stonehenge is believable and hauntingly told.

Maia, by Richard Adams (Signet, $5.95). Richard Adams, pastmaster at creating fictional worlds (i.e. Shardik and Watership Down), brings us another one in the Beklan Empire, setting for this, his most recent novel. Maia is a beautiful young maiden sold into slavery among the mythical Beklans. This is her story, an account of how she exercises her political and erotic power to gain ascendance among her captors. NONFICTION

Testament to the Bushmen, by Laurens van der Post and Jane Taylor (Penguin, $10.95). Published to complement a BBC-TV series, this passionate introduction to the Bushmen of the Kalahari Desert of South Africa -- historically the first inhabitants of that troubled land -- describes their way of life. Modern civilization is destroying the culture of this remarkably gentle people; and in a deeply felt afterword, Sir Laurens argues that the Bushmen represent the best qualities of humanity and that their extinction is a crime against ourselves.

A Palace for a King: The Buen Retiro and the Court of Philip IV, by Jonathan Brown and J. H. Elliott (Yale University Press, $14.95). In the 1630s a palace was built on the outskirts of Madrid for the youthful Philip IV, King of Spain. Though Spanish power was in decline in the 17th century, it was the Golden Age of baroque art; and the architectually rather simple Buen Retiro Palace was opulently ornamented with works by Vala'zquez, Rubens, Poussin, Claude Lorrain and many others. This magnificently illustrated and elegantly researched volume is at once cultural and political history.

Second Indochina War Symposium: Papers and Commentary , edited by John Schlight for the Center for Military History (Government Printing Office, $6.50). In November 1984 the U.S. Army convened a symposium of scholars, soldiers and diplomats to talk about the Vietnam War, which had ended a decade before. Here are the papers presented at that symposium, with commentary. Among the experts represented are George C. Herring, Walter LaFeber, Douglas Pike, Allan E. Goodman, Gen. Bruce Palmer Jr., Ronald H. Spector and Norman Graebner.

The Reign of the Ayatollahs: Iran and the Islamic Revolution , by Shaul Bakhash (Basic Books, $9.95). Many experts say this is the best book on the internal aspects of the Iranian revolution. Accordingly less attention is paid to the affair of the American hostages and more to the domestic Iranian politics of, say, land redistribution. A new concluding chapter suggests that the revolution has gone so far in its economic aspects that the prospects for the restoration of the old regime, even in a vastly liberalized form, are dim indeed. The author teaches history at George Mason University was formerly an Iranian journalist.

In Peace and War: Interpretations of American Naval History, 1775-1984: Second Edition , edited by Kenneth J. Hagan, and Against All Enemies: Interpretations of American Military History From Colonial Times to the Present, edited by Kenneth J. Hagan and William Roberts (Greenwood Press, $18.50 each). These two expensive volumes, edited by two Naval Academy historians, have been hailed as the most important introductory histories of the nation's armed forces that have appeared in decades -- of major interest to scholars, policymakers and active-duty personnel. In each, the cream of U.S. military and naval historians discuss their period of specialization -- thus in the Army volume Michigan's John Shy looks at the colonial wars of the 18th century, and in the Navy volume Annapolis' Robert W. Love Jr. examines the high stragegy of a two-ocean war in 1939-45. The books' value is enhanced by their contemporaneity: Col. Harry Summers Jr. discusses Army policies and tactics after Vietnam, and Floyd D. Kennedy Jr. looks at the Navy's fortunes under presidents Carter and Reagan.

Freedom Rising , by James North (NAL, $8.95). This account of South Africa's snow-balling black revolution is by a young American who spent 41/2 years traveling in that country. His portraits of South Africans of all colors and political stripes are often predictable. Yet one can hardly fail to be fired by his righteous indignation at apartheid's cruel rigidity, which exacts a price not only from the powerless but from the powerful as well.

Backpacking: One Step at a Time , by Harvey Manning (Vintage, $8.95). Here is a comprehensive guide to backcountry trekking -- from selection of equipment to preparation of food. The bad news about trail food is that it's usually not very good, but the good news is that, after a hard day's hike, almost anything tastes fine. The problem is that food weighs, but the author assures us that with careful planning a hiker can do well by himself on two pounds of food a day, and with very careful planning on 1 1/2 pounds. Speaking of weight, the author also claims that the physically fit sleep warmer than the flabby and overweight, "a terrible blow to jiggly folks who thought they had one advantage, at least, over skinny athletes." Finally, it should be noted that this book runs to 477 pages, which makes it fairly weighty itself: the moral is, one should familiarize himself with its guidelines but leave it at the trailhead.

Women Coming of Age , by Jane Fonda (Fireside/Simon&Schuster, $10.95). Written for "Women of a certain age," this useful book is full of information about diet, exercise, and what used to be known euphemistically as "feminine hygiene." Inspite of the disgustingly glamorous pictures of Fonda, the message here is that wrinkles are inevitable with aging, and so is a little sagging. But with exercise, and sensible eating habits, good health can be the within the grasp of all, regardless of age.