Shuttlecock and The Sweet-Shop Owner, by Graham Swift (Washington Square, $7.95 each). When Graham Swift's Waterland was published in the United States last year, it was greeted with critical acclaim, echoing the assessment of British critics who had voted it one of the Booker Award nominees. Now that Swift is established on this side of the Atlantic, Washington Square is bringing out his earlier work. Both Shuttlecock and The Sweet-Shop Owner are psychological novels, the first a thriller about a son who delves into the circumstances of his father's spying activities during World War II, the second a more domestic novel about a candy-shop owner and his family. Like Waterland, these earlier stories involve long-kept secrets which spill over into the present and infect the families who've kept them with dark difficulties. Graham Swift's narratives twist and turn, knotting together inexorably the past with the present, sweeping us along steadily.

A Fan's Notes, by Frederick Exley (Vintage, $5.95). This is one of the great American novels, extolled by readers as various as William Gass, Kurt Vonnegut, James Dickey and Robert Penn Warren. This "fictional memoir" counterpoints the sad, failed life of Fred Exley -- would-be writer and sportsman -- with the majestic eminence of critic Edmund Wilson and the graceful mastery of football player Frank Gifford. What makes Exley's life magical though, despite aborted marriages, love affairs, and madness, is his prose: rabidly funny, ironic, delicious as gin and tonic. NONFICTION

Gorillas in the Mist, by Dian Fossey (Houghton Mifflin, $10.95). Based on 15 years of field study in the Virunga Volcanoes of Central Africa, this is an informed and loving portrait of the endangered mountain gorilla. Picked by the renowned archeologist Louis Leakey to conduct the study, Fossey drew upon the assistance of several benefactors, notably the National Geographic Society, to make films, write monographs, and fashion this long and fascinating book on what she calls "the greatest of the great apes." Among her remarkable findings is that the best way to distinguish individual members of the species is by their noseprints.

Timberline: Mountain and Arctic Forest Frontiers, by Stephen F. Arno and Ramona P. Hammerly (The Mountaineers, 306 2nd Ave. W., Seattle, Wash. 98119, $9.95). Here is a guide to one of the windswept outer reaches of the world, the boundary above which trees can no longer survive. Just where the line runs on a given peak is a matter of definition -- should shrublike trees, called "krummholz," be considered above or below the belt? Author Arno, who works as an ecologist for the U.S. Forest Service, makes these distinctions clearly. Illustrator Hammerly does them elegant black-and-white justice.

The Enlightenment: A Comprehensive Anthology, edited with introductory notes by Peter Gay (Touchstone, $15.95). The master of the Enlightenment, Yale historian Peter Gay, here collects the essential documents of the age, as well as material from such precursors as Tacitus. Included are Pope's "Essay on Man," Winckelmann on Greek sculpture, Lessing on Jews, and several pieces by the figure with whom Gay has most sympathy: the tranquil Scottish iconoclast, David Hume. Gay notes that, for all their hope and optimism, "in general the philosophes thought that while improvement was now more likely than ever before, it was by no means inescapable, and was in any event often temporary."

The Druids, by Stuart Piggott (Thames and Hudson/Norton, distributor, $10.95). This introduction to the fabled pre-Roman religion of Celtic Gaul and Britain begins by asking why such a minor sect has maintained so strong a hold on European and American imaginations. The Druids represent Primitivism and the Noble Savage, points out the archeologist author. In addition, the myths that have accreted about them -- that they built Stonehenge, for example -- make for a powerful image of precocious wizardry. Piggott's well-illustrated volume presents the facts -- and reasonable speculation -- about what the Druids built, how they lived, and whom they sacrificed.

The American Railroad Passenger Car, by John H. White, Jr. (Johns Hopkins, two volumes, $17.95 each). Outsized, profusely illustrated (blueprints included) and lovingly detailed, these two volumes constitute a noble tribute to an age of refined, leisurely and comfortable travel. One of the photos presents the private car of George Pullman himself -- the last word in ornate rolling stock. There is also an ad for Horton's Reclining Chair for Cars (c. 1870), which "will greatly increase local night travel." CHILDREN'S

I Can Build a House!; Where's My Daddy?; I Can Ride It!; I Can Take a Walk, all by Shigeo Watanabe, pictures by Yasuo Ohtomo (Philomel, $3.95 each; ages 2-5). These charming picture books are part of a series -- "I Can Do It All by Myself" is the label -- designed to help toddlers develop independence. Whether a picture book can do that is anyone's guess; most children will enjoy the medium here, regardless of the message. Yasuo Ohtomo's brightly colored illustrations are full of life, motion and wit, while the text builds to a little climax in each story of childish adventure.

Who Will Be My Friends? by Syd Hoff (Harper Trophy, $2.50; ages 4-8). Syd Hoff's books, which have been with us for decades, have an old-fashioned look about them -- maybe it's the beenie baseball caps the little boys wear -- but there's a timelessness in their themes. Hoff's characters want to "belong," be accepted. And the little boy here, who's just moved to a new neighborhood, is no exception. The message here, and there always is one in Hoff, is that if you amuse yourself, you'll soon find others to play with. Not bad advice!

The Royal Book of Oz; Kabumpo in Oz; The Cowardly Lion of Oz; Grampa in Oz; The Lost King of Oz; The Hungry Tiger of Oz, all by Ruth Plumly Thompson; all illustrated by John R. Neill (Ballantine/Del Rey, $5.95 each). After the death of L. Frank Baum, who created and wrote about Oz in 14 novels, Ruth Plumly Thompson became his designated successor. Over the years Thompson contributed 19 more installments to the chronicles of the royal kingdom, but her books have recently been hard to come by. Having successfully republished the Baum books, the Del Reys have happily decided to keep a good thing going; so here are the first six Thompson novels. There is clearly a lot more to Oz than Dorothy ever suspected when she first crashed down in the land of the Munchkins.