SYLVIA PLATH A Biography by Linda W....

SYLVIA PLATH A Biography by Linda W. Wagner-Martin (St. Martin’s Press: $12.95) Though the facts of Sylvia Plath’s life are readily available, the central riddle of her existence and suicide is unsolved.

Plath was born Oct. 27, 1932 to well-educated parents. Her father’s death when she was 8 closed the chapter on her nearly idyllic childhood. She began writing poetry as a sophomore in high school and won a scholarship to Smith College.

But in the summer after her junior year, Plath tried to kill herself and almost succeeded--taking nearly a full bottle of sleeping pills and hiding beneath her home in the crawl space under a first-floor bedroom.

Graduating summa cum laude from Smith, she received a Fulbright Fellowship to Cambridge University in England, met a fellow poet, Ted Hughes, and married him in 1956. They had two children. She and Hughes, who had taken a lover, separated in the summer of 1962. But on Feb. 11, 1963, Plath killed herself by breathing noxious fumes from a lighted oven.

Drawing from Plath’s manuscripts and work sheets, her journals and correspondence (the journals are incomplete: Ted Hughes destroyed her last one to spare the children from reading it, he says), and from more than 200 interviews, Linda Wagner-Martin has created a masterful biography of the tragic poet, who wrote to her mother: “I am a genius of a writer; I have it in me. I am writing the best poems of my life; they will make my name.”

AN ADULTERY by Alexander Theroux (Collier Books / Macmillan: $8.95) “The worst thing about infidelity is not that it breaks your heart, but that it turns your heart to stone,” says the narrator of Alexander Theroux’s novel.

The affair begins simply enough. Christian Ford, a painter, is visiting an art gallery in St. Ives when he first sees the lovely Farol Colorado. When he returns to the gallery a few days later to have a picture framed, she smiles at him; they exchange a few words, and he gives her his address in town.

Farol appears at his door one night. She’s married, but not very happily; he has a girlfriend, but she lives in Boston, far from the town in New Hampshire where he teaches at a prep school.

The two fight intimacy--in syncopation. Farol leaves her husband, returns to him, then begins another affair with another man--a doctor.

“An Adultery,” told in the first person, tells the story from the man’s point of view--reflective, betrayed, he discovers that Farol is a serial adulteress: “She’d gone from man to man like a monkey on ropes!” And he seeks revenge.

A compelling, finely wrought and ultimately tragic novel.

MODERN DICTATORS Third World Coups Makers, Strongmen and Populist Tyrants by Barry Rubin (A Meridian Book / New American Library: $8.95) In this informative, well-researched text, Barry Rubin explains how dictatorship became the dominant form of government among Third-World nations through the power of ideology, religion and nationalism. He examines the varying styles of despotism, from the traditional dictators such as Anastasio Somoza and Ferdinand Marcos, to “modern” dictators such as Fidel Castro and the Ayatollah Ruhollah Khomeini, and spells out the challenges posed to the United States and other democratic states.

The “modern” dictator mobilizes public support and fanaticism, often gaining confidence by sponsoring anti-Americanism and terrorism: “Iran’s Ayatollah Khomeini held U.S. diplomats as hostages and defied America to do something about it. Libyan leader Muammar al-Qaddafi threatened to cut off President Reagan’s nose.”

The failure of U.S. policy makers under Presidents Carter and Reagan indicates an ignorance of the mechanics of these new Third-World regimes; Barry Rubin’s work will be a valuable source book.

SENT FOR YOU YESTERDAY by John Edgar Wideman (Vintage Books: $6.95) Brother Tate stopped talking for 16 years until he died, shortly after his son, Junebug, died in a fire on the Fourth of July. But he could “cat sing and imitate all the instruments in a band.”

Winner of the P.E.N. / Faulkner Award for fiction, “Sent for You Yesterday” is one of three novels set in Homewood, a black community on the outskirts of Pittsburgh, by the author of the best-selling “Brothers and Keepers.”

“Sent for you yesterday, and here you come today,” sang Jimmy Rushing, backed by Count Basie, from the stereo, when Lucy Tate got the 5-year-old boy that Brother had nicknamed Doot to get up and dance. Lucy, Doot’s Uncle Carl, and Brother are at the core of this novel. Interweaving their voices and Doot’s adult memories, Wideman creates an original, seamless narrative, tracing their lives and the changing community from the 1920s to the 1970s.

MUSEUMS OF SOUTHERN CALIFORNIA by Sara LeBien (Gibbs Smith, Publisher, Layton, Utah: $11.95) This comprehensive guidebook lists more than 170 museums from Santa Barbara to San Diego--art galleries, nature centers, historic homes and many others--with descriptions of the exhibits as well as directions on how to get there.