To celebrate its 50th anniversary, the National Book Foundation is planning a literary glitzfest next month in Manhattan. Writer and comedian Steve Martin will host the ga-ga gala; the queen bee of book clubs, Oprah Winfrey, will be honored; and the National Book Awards will be presented.

In contrast to the high-glam affair, the list of finalists for the awards--which was announced yesterday--looks pretty low-key and homely. In fact, the sexiest book on the list, at least the one that has drawn the most attention, is "Plainsong," a plain-spoken tale of life in a small Colorado town. The book was featured prominently in the Book Sense 76, a monthly newsletter for independent booksellers, and has received positive reviews from the American Library Association and Kirkus Reviews.

"I was very surprised and thrilled," said soft-spoken author Kent Haruf (rhymes with sheriff), a professor at Southern Illinois University. Haruf, 56, published his first novel when he was 41. "Plainsong" is his third. "I've been surprised all along by the reception of this book."

He added, "While I was working on the book, I was discouraged any number of times. It wasn't as good a book as I had hoped to write."

Haruf planned to celebrate yesterday afternoon by keeping his appointments with students and walking the dogs when he got home. He said he had not read the other finalists: "House of Sand and Fog" by Andre Dubus III; "Who Do You Love?" by Jean Thompson; "Hummingbird House" by Patricia Henley; and "Waiting" by Ha Jin.

Terri Merz of Chapters Literary Bookstore on K Street has read the Dubus novel. She has been recommending "House of Sand and Fog" to her readers since it was published. The novel about an ambitious Iranian immigrant, she said, is "nothing short of a masterpiece."

"It's a devastating, dead-on portrayal of the hope and despair implicit in the American dream," Merz said. "It's one of the strongest pieces of fiction I've read all year."

Notoriously independent, the National Book Awards often honor books of high literary quality but little commercial appeal. Such heavily hyped books as "Dutch: A Memoir of Ronald Reagan" by Edmund Morris and " 'Tis" by Frank McCourt did not make the list.

"To me as a reader, as an observer of the literary scene," said foundation executive director Neil Baldwin, "it's a snapshot of the concerns of our society right now."

For a book to be considered for the 1999 prize, the author must be a U.S. citizen and the book must have been published between Dec. 1, 1998, and Nov. 30, 1999 (latecomers are judged in galley form). "American citizenship," Baldwin said, "is something we're very, very assiduous about."

Baldwin, in fact, called Pantheon Books, publisher of Ha Jin's "Waiting," to make sure the author was a citizen. Ha Jin was a soldier in the People's Liberation Army of China for six years before moving to the United States in 1985; he became a citizen in 1998. He teaches English at Emory University in Atlanta.

The awards are divided into four categories: fiction, nonfiction, poetry and young people's literature.

The finalists in nonfiction are "Woman: An Intimate Geography" by Takoma Park resident Natalie Angier; "Black Hawk Down: A Story of Modern War" by Mark Bowden; "Embracing Defeat: Japan in the Wake of World War II" by John W. Dower; "Places Left Unfinished at the Time of Creation" by John Phillip Santos; and "Secrets of the Flesh: A Life of Colette" by Judith Thurman.

Angier, a Pulitzer Prize-winning New York Times reporter, was celebrating her nomination at home yesterday. "I had a very bad migraine all day," she said, "so I probably won't be breaking out the champagne."

She laughed and said, "When I won the Pulitzer Prize, I had a root canal done."

Of "Embracing Defeat," a 676-page tome, The Washington Post said: "For anybody who knows modern Japan, it is an endlessly fascinating explanation of why things work the way they do."

The poetry finalists are "Vice: New and Selected Poems" by Ai; "Vita Nova: Poems" by Louise Gluck; "Configurations: New & Selected Poems 1958-1998" by Clarence Major; "The Pilot Star Elegies" by Sherod Santos; and "Repair" by C.K. Williams.

Of Clarence Major, Kirkus Reviews said: He "writes poetry with the resistant, angular surface of tumbled brick. As if the poem has been literally smashed. An improvisational, jazz-like quality."

Finalists in young people's literature are "Speak" by Laurie Halse Anderson; "The Birchbark House" by Louise Erdrich; "When Zachary Beaver Came to Town" by Kimberly Willis Holt; "The Trolls" by Polly Horvath; and "Monster" by Walter Dean Myers.

Does being a NBA finalist help the sales of a book? "Being a finalist does have an impact these days," said Paul Bogaards of Alfred A. Knopf, publisher of "Plainsong." "Our bookselling partners are all at-the-ready to display the nominees in their stores, usually on front tables. Same thing with the online bookstores."

Some past winners of the National Book Award, such as "Charming Billy" by Alice McDermott, "Middle Passage" by Charles Johnson, "Cold Mountain" by Charles Frazier, "The Shipping News" by Annie Proulx and "All the Pretty Horses" by Cormac McCarthy, went on to become bestsellers after winning the top prize.

This year 20 judges, five for each category, shuffled through 881 titles from 207 publishers to determine the 20 finalists. The panel included authors Charles Johnson, Terry McMillan and Neal Gabler. Every finalist is given $1,000 and a bronze medal. Winners in each category will be given $10,000 and a crystal sculpture. At the awards ceremony on Nov. 17, Oprah Winfrey will also receive a crystal sculpture, designed by Tiffany & Co.

CAPTION: Steve Martin will be at next month's National Book Awards gala.