It's easy to tell the royalty at the American Booksellers Association's annual convention: They're the only ones who aren't wearing name tags.

Princess Michael of Kent, resplendent in a blue and white dress ("It's American made, but I never publicize my designs") and pearl and diamond earrings, is holding forth at the Weidenfeld and Nicolson booth on her forthcoming book, "Crowned in a Far Land: Portraits of Eight Royal Brides."

"Think of the croissant. You think the croissant's French, don't you? [Nods from her audience of five booksellers.] But it's from Vienna. And who were at the gates of Vienna? The Turks. The pastry cooking of the Turks and the crescent of the Turks produced the croissant . . . " And she goes on like this with her cross-cultural studies.

Each Memorial Day weekend, 15,000 publishers, booksellers, agents and even a few authors gather together in a pleasant city to do business and to party, not necessarily in that order. "It's more than just a booksellers' convention," says Washington literary agent Rafe Sagalyn. "It's a rights fair, flesh-pressing, deal making and summer camp all rolled into one. And sometimes a good time, too."

Throughout her lecture, the princess and her retinue of publicists are on guard against press intrusion. "Oh you're leaving?" she says to a reporter. "Good!" Switching happily back to her audience, she leaps into the fray again: Royal brides "all rode horses . . . and they all rode like dervishes. It was a way to relieve tension and let off steam." The princess adds that she, of course, rides regularly.

"It's like working out. You all work out in America, don't you?" The audience -- which is down at the moment to two flabby booksellers and a chunky man from Oakland with his shirt almost completely unbuttoned -- agrees warily. "Then you see what I mean," says the princess, and she smiles a radiant smile.

"It is fun to have fun," says the Cat in the Hat, "but you have to know how." Thousands of convention-goers know how: They go to any of more than a hundred ABA autographing sessions, wait in line for 15 to 45 minutes and emerge with a signed book or poster, gift of the publisher.

Dr. Seuss, a k a Theodor Geisel, dapper in gray suit and slicked-back white hair, polishes off 1,000 copies of "The Cat in the Hat" in an hour, including time for hearing how one bookseller's friend has a chicken that lays green eggs -- the perfect anecdote for the author of "Green Eggs and Ham." "Congratulate the hen for me, will you?" Seuss says amiably. During his thousand scribbles the 82-year-old Seuss rarely slackens, although he does note at one point, "I sure wouldn't stand this long for my autograph."

At a nearby table, columnist George Will is autographing with patient grace copies of a poster promoting his forthcoming "The Morning After: American Successes and Excesses 1981-86." "If there was something like this in ancient Athens, Aristotle would have showed up with the 'Ethics' and said, 'Here, read this, it's a heck of a book,' " he comments. And who would George Will stand in line for? "David Hume [1711-76] . . . Anne Tyler . . . I'd love to have a color photograph of Anita Brookner -- isn't that a handsome looking woman?"

Walter Cronkite and Carol Burnett are seasoned pros, so when they are upstaged by a novelist who is barely known to most of the audience, it can only be the luck of the Irish.

"Nobody but prohibitionists would have a meeting this early in the morning," Cronkite tells the Sunday author breakfast. The audience giggles weakly. The former CBS anchor, who is promoting "North by Northeast" (Oxmoor House), an account of a sailing trip up the New England coast, goes on to tell the crowd of 2,000 -- including a man with a parrot on his shoulder -- that he is finally ready to write the autobiography he contracted to do a quarter-century ago. The book, he says, will concentrate on his formative years: "Up to age 10 . . . Think of the drama . . . the trauma. The romance with my nursemaid. We'll call it 'Mammy Dearest.' "

Cronkite is followed by the genial Pat Conroy, author of "The Prince of Tides" (Houghton Mifflin), who says that "speaking after Walter Cronkite, I must sound like a parakeet to you." Not really. His punchy voice, a southern drawl chopped up into bite-size pieces, is actually more lively than Uncle Walter's stentorian tones. But it is the content of Conroy's talk that holds the audience rapt.

He first tells how his parents met on the streets of Atlanta: "my father pursuing her as Irishmen will do; my mother ignoring him, as southern girls are supposed to do. He begged her for a phone number; she got on the bus. My father was in a footrace. He ran after her until my mother leans out and screams out the phone number to my father. As children, we would hear the story and scream, 'Tell him the wrong number, Ma!' "

The marriage of two such dissimilar types had a good deal of friction, which Conroy recorded in his novel "The Great Santini." When it came time to make the movie, the family members argued about which actors they wanted to play them. It was a topic that resurfaced when he was writing his new book and his mother was dying of cancer.

"The prettiest woman I've ever seen reduced to 80 pounds . . . She said, 'Let me ask you one thing.' I said, 'Mom, you're in a great position to bargain.' And she said, 'Don't make me like this. Make me beautiful.' I said, 'Mamma, I'm going to make you so beautiful . . . because you taught me right and raised me right, I am going to lift you off that bed, and I can set you singing and dancing and I can make a beautiful gift for everyone in the world.' And my mother said, 'I'd like Meryl Streep to play the role.' "

By this point, the booksellers aren't sure whether to cheer or weep -- but they know they have to order the book, which is the point of the breakfast. Burnett, the last speaker, seems almost an afterthought.

Posthumous works are the dominant trend for the fall. The list ranges from Vladimir Nabokov's "The Enchanter" (a 1939 work, long believed lost, that was apparently a dry run for "Lolita"; to be published by Putnam) to John Lennon's "Skywriting by Word of Mouth" (a collection of previously unpublished stories, songs and drawings; Harper & Row) to volumes four and five of L. Ron Hubbard's science fiction decalogy (Bridge Publications).

The late Truman Capote figures prominently in several publishers' plans. Random House is issuing "Answered Prayers," or at least the three chapters that appeared in Esquire a decade ago. Random also has a "Capote Reader," while John Malcolm Brinnin has written a portrait, "Dear Heart, Old Buddy" (Delacorte), and Gerald Clarke is on hand with the bio, called simply "Capote" (Simon and Schuster).

If there are no other major trends in evidence there are at least a few trendlets, as several publishers simultaneously seize on the same topic -- an occupational hazard when you go to the same parties:

*The fascination with Marilyn Monroe shows no signs of flagging. Roger Kahn tackles the star's marriage to Joe DiMaggio in "Joe and Marilyn" (Morrow), Andre de Dienes has early photos in "Marilyn Mon Amour" (St. Martin's Press) and, most intriguingly, Gloria Steinem writes about the sex goddess from a feminist viewpoint in "Marilyn" (Holt).

*Anatoly Shcharansky, who is writing his own story of his 12 years in Soviet jails, is the subject of at least two books: the just-released "Shcharansky: Hero of Our Time," by Martin Gilbert (Viking), and "Anatoly and Avital Shcharansky: The Journey Home," by the Jerusalem Post (HBJ).

*As usual, there are the big books that should make cash registers merry. Gary Devon, whose first novel, "Lost," will be published by Knopf, is being presented as a sort of thinking man's Stephen King, while King himself is represented by "It" (Viking). Also expected to do well: James Clavell's "Whirlwind" (Morrow), the fifth in his Asian saga; Karleen Koen's "Through a Glass Darkly" (Random House), a historical first novel; former Washington Post reporter Sally Quinn's "Regrets Only" (Simon and Schuster); and Robin Cook's "Outbreak" (Putnam).

ABC reporter Sam Donaldson, present to promote his "Hold On, Mr. President!," has thrust upon him a copy of a book titled "I Feel Much Better." "I never accept payola, but I'll accept this," says Donaldson, who promptly hides the book under a bulky envelope he is carrying. He is "absolutely" looking forward to being on the other side of the microphone: "I've dished it out for a long time. I guess I want to see how it is to take it." Among the anecdotes in the book, according to the Random House catalogue: the night he mistakenly thought Barbara Walters wanted his body.

In addition to hype, this convention also produced some real news.

Real estate and publishing magnate Mortimer Zuckerman chose the ABA to announce he was selling the Atlantic Monthly Press to Carl Navarre, a Chattanooga businessman. Not exactly coincidentally, AMP Editor in Chief Harold Evans also jumped ship, over to the new firm of Weidenfeld and Nicolson.

And today, Playboy magazine and the Council for Periodical Distributors joined the ABA in asking a federal court to stop Attorney General Edwin Meese from compiling and releasing a blacklist of alleged pornography distributors.

"I was never a sex symbol," says Burnett. " . . . Now I'm growing into it."

Or maybe something even better. Upstaged by Conroy at the author breakfast, Burnett rebounds at a press conference and on the convention floor to become a hit. "One More Time" (Random House) covers her life to age 26, when she permanently got off unemployment. It sounds like the kind of life they used to make tear-jerkers of: born in the wrong part of Hollywood, parents both alcoholics who died at age 46, and her childhood home a single room shared with her grandmother, a "Christian Scientist who took a lot of medicine on the side, and always got well in time for the movies."

Contrary to the usual style of celebrity biographies these days, Burnett wrote the book completely herself, as a letter to her three daughters. She says she had no interest in writing an "and-then-I-met-Cary-Grant" book -- "although I did get to meet him. And it was worth it." She gives one of her characteristic whoops.

When she was growing up, "we didn't know alcoholism was a disease. My dad . . . was always very sweet when he drank. In fact, he got sweeter. I didn't realize what a terrific person he was until I read what I wrote about him." But she also mentions finding a letter recently that her father had written to her when she was a child. "Dear Pumpkin Kid," it said. "Daddy hasn't had a drop of hooch in three weeks and he won't anymore as long as you pray for me and are a good girl."

"He didn't know what kind of trip he was laying on me," Burnett said. "Of course I was praying like crazy, but he did have a drop of hooch again."

With her own daughters, she intended to be "Irene Dunne or Loretta Young. Everything would be wonderful, like on 'The Donna Reed Show.' They would never see me cry, upset, or hear me say a dirty word . . . Well, kids aren't dumb, and it was a disservice to them. They knew I was pretending . . . And how could they then get upset if their mom was going to be so perfect all the time? So I decided to just be myself. The first time I said a cuss word, they all just beamed."

Hanging out at cartoonist Berke Breathed's party is John Ehrlichman. Relaxed, tanned and bearded, the former Nixon administration domestic affairs adviser could be called California mellow, except he lives in Santa Fe, N.M. At the convention to push his new novel, "The China Card," Ehrlichman says he doesn't see the old crowd anymore. He visits Bob Haldeman occasionally, but Nixon never: "I never did have a social relationship with him."

Although he claims to be completely removed from the political scene, Ehrlichman does say, "I like George [Bush] very much." And if he got a call from President Bush, would he serve? "No. For one thing, I know my wife wouldn't be at all interested."

As Saturday night wears on, the humidity increases and many give up the idea of party hopping. At the Old U.S. Mint a party thrown by Crown Publishers for Martha Stewart's "Weddings" features dessert specialties from famous area restaurants. The hosts have spent lavishly, but the weather does the scene in. Says one grim partygoer: "This must be what it's like to get married in Hell."

Putting an ABA convention in New Orleans is like encountering a mugger in a dark alley: It's not exactly friendly territory. According to a recent Commerce Department survey, New Orleans, the nation's 20th-largest city, doesn't even rank among the top 50 for total book sales.

In a way, perhaps that's appropriate. While the number of exhibitors was up from 8,220 last year in San Francisco to 10,286 in New Orleans, a significant percentage of this growth was due to such nonbook items as videos. And the number of booksellers attending dropped sharply, from 7,636 to 4,467.

Esthy Adler of the new Washington publishing firm of Adler and Adler puts the best face possible on the turnout.

"I don't think that the ABA is the place to do business anymore," she says. "Very few publishers are here to write orders. We're here to see people, and be seen by those who haven't heard of us."

One book that isn't seen at the Adler booth is the memoirs of Kurt Waldheim, who has been under fire over his role in the German military in World War II. "We still think it's good on its subject, the United Nations," Adler says, "but we're not promoting it."

One comment seems to sum up the general convention mood. "There's no hype. Everyone's playing it safe," says Marcy Posner, director of subsidiary rights for Pantheon.

In 1987, the ABA comes back to Washington. In the book business, you always have hopes for next year.