SERIOUS as it was, the American Booksellers Association Convention was not all business. Publishers and booksellers may not wear funny hats or shoot off water pistols, but they do like to party.

One of Atlanta's marvels is the disco Limelight; swimming around under its clear plastic dance floore were live sharks. A few weeks back the disco had a panther under the plastic but the humane society had angrily fetched it away. Apparently nobody cares what happens to sharks, and it was a popular place to shake your booty. More than 700 conventioneers turned up to rock and roll at Tingles where a lookalike, soundalike band called Bootleg played Beatles music only, to celebrate the Delilah Communications/Bantam Books publication of The Compleat Beatles . The party was scheduled to end at 11 p.m. but when 2 a.m. rattled and rolled around, the ABA was still dancing.

More high stepping at the Confederates Ball which Berkley held at Anthony's Antebellum Plantation. Thomas Keneally, author of The Confederates , who was decked out in a Johnnie Reb uniform borrowed from the Gone With the Wind Museum, was almost upstaged at this affair, not by the dancing or the chateaubriand but by the dessert, which was wheeled in to the jubilant strains of "Dixie," ablaze with sparklers and flying a Confederate flag.

New American Library held an invitational tennis tournament for their author Arthur Ashe who autobiography Off the Court will be published this fall. While strawberries, champagne, quiche and pate were served up on one tennis court, tennis balls were served up on another as champion Ashe defeated the nine brave but foolish souls who volunteered to play him.

In between parties I went to look for the so-called Big Books upcoming this fall. Nothing rose up from the convention floor to sock you between the eyes, but these are all safe choices -- books by authors who have Been There Before and are no doubt Going There Again. I think that Putnam showed strong -- they have Red Dragon by Thomas Harris, author of Black Sunday . Reprinters have been reading it with tongues hanging out, and we hear that Harris' agent Gloria Safire is holding the film rights hostage with a demand for $2 million. Putnam also has Robin Cooks's Fever and A Green Desire by Anton Myrer, author of The Last Convertible . Dutton is glowing over John Irving's new novel Hotel New Hampshire and Joyce Carol Oates' Angel of Light . Holt has a fat anthology from Garry Trudeau, The People's Doonesbury ; Stephen King has another sure bet coming from Viking, Cujo ; the prolific and popular Danielle Steele and Phyllis Whitney have ne2w novels, respectively Remembrance from Delacorte and Vermilion from Doubleday. Saul Bellow's new novel is The Dean's December from Harper & Row, which also offers An Indecent Obsession by Colleen McCullough whose Thorn Birds broke a lot of publishing records. Delacorte also has Rona Jaffe's latest Mazes and Monsters and Irwin Shaw's latest Bread Upon the Waters . St. Martin's has another M.M. Kaye novel, this one called Trade Wind . Random House also presented an excellent fall list, with their biggies: L.L. Bean's Guide to the Outdoors, Social Studies by Fran Lebowitz, Chameleon by William Diehl, and a novel I kept hearing about, Yesterday's Streets by Sylvia Tennenbaum. Crown was offering another novel I kept hearing about called Traditions , the saga of a show business family, by Alan Ebert with Janis Rotchstein.

I think all of the above have a very good chance at this autumn's best-seller lists, and a couple appear born to rise to the top. I saw two enormously appealing books: Workman is offering The Illustrated Garden by a young Englishwoman, Sara Midda, whose delicate illustrations and charming text have been fashioned into an elegant gift book for garden lovers; and Sewing Classic Clothes for Children , a clear guide with pretty sepia illustrations for making lovely pinafores, sailor suits, infants duds and so forth from Hearst Books. The author is Kitty Benton who is married to Nicholas Benton, public relations director of Time-Life Books, Alexandria, Virginia. Nick was beaming proudly around the convention floor reminding everybody at least three times that dear Kitty's dear book is a Full selection of the Book-of-the-Month Club's craft club.

Putnam threw Art Buchwald a mammoth dinner party at Betty Talmadge's beautiful Lovejoy Plantation. Lovejoy was Margaret Mitchell's inspiration for Twelve Oaks in Gone With the Wind and, sure enough, stereo speakers were rendering the Tara theme as we were shown through the gracious rooms of the Big House. After we had admired the house and petted the animals -- Rabbitt E. Lee, Billy T. Sherman the goat and a spanking-clean piglet named Ulysses S. Grunt, we got down to the serious business of fried chicken, country ham and grits.

Buchwald, who was on hand affably to plug his new book Laid Back in Washington , reminded us that this was a Washington book and therefore filled with sex and violence. Then taking a pot shot at Kit Williams' Masquerade, he informed his audience that he had laced his own book with clues "to enable the reader to find the treasure buried somewhere in the continental United States. By following the clues he will find in a silver chest somewhere in this country his social security check. Also, to make sure there are no returns, we have sealed an explosive device between the pages and if a store does not sell it in three weeks the book will explode on the shelves and destroy every copy of Nobel House ."

John Irving's publisher, Dutton, held an intimate dinner party during which the amiable Nick Benton told us that Time-Life books is on the receiving end these days of almost 2,000 resumes a month. When I naively remarked that it was reassuring that kids still wanted to get into the book business, portly book critic Eliot Fremont-Smith snorted, "Kids! they're Democrats!" which dissolved our table. When Irving got up to say thank you, he told us that he and his son had had reservations on the flight out of Chicago to L.A. that crashed during the ABA convention two years ago, killing everyone on board. He had changed his reservations at the last minute because the Tomorrow Show had changed the night they wanted to film him. On the way back from the convention Irving's son asked, "Don't you feel stupid to owe your life to a T.V. show?" Irving's answer was and still is "yes." He went on: "I went to the New York Review of Books party in L.A. It was held at a Catholic college, a wonderful looking place catered as such parties are. And the women serving us were wearing traditional French chambermaid costumes -- black and white and short and fetching. I was standing at this party with Henry [the late Henry Robbins was John Irving's editor on The World According to Garp] and we were observing these chambermaids going to and fro. Standing in the wings of the party were some of the nuns whose domicile this was and they wwere also in black and white but in much different habits. They were the most interested of all in the chambermaids going to and fro, and I remember that Henry . . . he was in good spirits . . . said to me, 'I want you to remember that literature isn't always like this.'"

Among the not to be missed events of the '81 ABA was The Wedding. The Berkley/Jove do in which bookseller Ronda Wonderman (a name that has passed forever into publishing trivia) exhanged nuptial vows with bookseller Charles Young. The entire shebang -- wedding, reception, honeymoon -- was handed to the happy couple gratis, much of it donated by suppliers wanting credit for the wedding gowns, tuxes, flowers, honeymoon cruise, etc. The reason behind all this generosity was a new series of paperback romances coming from the publishers -- "Second Chance at Love." The judge who married the pair went on and on and on about the series, leading some of us to wonder why he didn't also give the publication dates, cover prices and ISBN numbers. "Tacky" was the word most often used around the convention, although it was mostly spoken through tight lips and gritted teeth by publicity directors of other houses who wished they'd thought of it themselves. And you know in the long run it was kind of sweet to watch a young woman and a young man make public commitment to each other. It was, no matter what kind of hype surrounds it, rather touching.