Blowing into the Algonquin Hotel one May afternoon in long black fabric pinned at the neck, a crocheted granny shawl she does not remove and high heels she instantly changes to workmanlike sandals, Claire Cook speaks in torrents. She's already laughing—high, happy gales that stun the stately room of tea-takers and cautious tourists—and moves in to embrace PW, who intercepts her between her whirlwind luncheon in the city with Barnes & Noble's Sessalee Hensley and her flight back home to the South Shore of Massachusetts. After the hot sale of her 2002 breakthrough novel, Must Love Dogs, and movie-in-the-works, Claire Cook's latest novel, Multiple Choice, this summer promises to gain the similar adoration of booksellers and golden treatment by her team of publishers, Viking/Penguin and NAL. Cook exclaims with astonished good nature, "I really have nothing to be in a bad mood about!"

As she breathlessly unravels her publishing coup—she spends 25 years not writing, then encounters instant acceptance for her first novel, Ready to Fall (Bridge Works, 2000), in her mid-40s, with help from virtually no one—Cook interjects her own bubbling disbelief in her good fortune. "Can you believe it?" squeals this former schoolteacher who has lived in the same town, Scituate, between Boston and Cape Cod, for most of her life. She is an open, pleasant, garrulous woman not quite 50, with short, dark hair; she speaks at a breakneck pace, exhausting her interviewer, who attempts to halt her with an upheld hand. Cook chatters: "I taught for 16 years, I had children, I did all those creative things, but I always had that nagging dream, and in my 40s, it hit me one day that this is midlife and I may never write a novel. I could go my whole life and not do the thing that in my heart I've always known I should do." Her voice quavers with emotion. "I just didn't know what my stories were yet."

In fact, her stories involve characters "in transition," who hold for her readers a spell of familiarity: a suburban mom in Multiple Choice grows fed up with being a "directionality coach" for "whiny, entitled" female clients and heads back to college at the same time her teenage daughter does; a divorcée in Must Love Dogs decides, at the prodding of her meddlesome Irish-American clan, to rejoin the dating circle by fashioning a not-entirely-truthful personal ad; while in Ready to Fall a sad swim-mom in a tired marriage finds personal expression (and sublimated sexual satisfaction) through e-mails to her writer neighbor suffering his own marital problems. Cook writes in the first person with self-deprecating humor—"Never mean," she insists. "If you have to be mean, you should be disqualified"—and her characters, judging from the enthusiastic response from her readers, ring true. "People most often say, 'Oh my god, you're writing my life,' " Cook enthuses. "I wondered if my appeal would be regional or suburban, but it cuts across every category you could pick. I think it's just the quirky parts of our life that are right in front of us, but maybe we never knew it was funny before?"

Having never attempted a novel, or written anything since college at S.I. Newhouse School of Public Communications at Syracuse University (not even thank-you notes, she adds, "because they would remind me of what I wasn't writing"), she began writing in the early mornings as she waited for her daughter at swim practice. She wrote in longhand on legal pads, then transcribed what she had onto her computer before she went to work at the Montessori Community School in Scituate. Quickly, she had a draft, but she didn't know a soul in the publishing business—"My connections were 20 years old!"—so she got a copy of Writer's Market and sent queries to agents. They wrote back to her, she recalls, giggling: "If your novel is half as funny as your query letter, you will definitely find someone. However, it won't be me."

For agents, Cook sought recommendations from authors whose work she admired—for example, Pull of the Moon directed her to Elizabeth Berg, who didn't write back immediately, so Cook submitted queries to smaller houses that didn't require an agent, such as Bridge Works, in Bridgehampton, N.Y.: "They had launched Tom Perrotta and Lorna Landrik, and I liked their novels," Cook says. "They were quietly quirky, and kind of interesting, but, honestly, they would look at me without an agent." And they bought Ready to Fall—a novel written in the form of humorous e-mails from the lonely matron "SwimSlave" to "Wanderlust," who turns out to be her next-door neighbor whose wife has left him—"right away, first time out, can you believe it?" Cook cries, reliving the moment of triumph in a trilling crescendo that sends newspapers rustling around the historic old sitting room. The luck of the Irish? It gets better. A correspondence with novelist Berg did ensue, leading to an invitation to join Berg's Cambridge writing group, where Cook and the other six members brought 10 pages of their work to each meeting to discuss—Cook worked on revisions for Ready to Fall, as well as the first stages of her next novel, Must Love Dogs. Berg took the liberty of faxing some of Cook's pages to her agent, Lisa Bankoff—who called the next day. Bankoff, who represents primarily literary clients such as Ann Patchett and Anne Roiphe, found the first chapter of the novel, in which the protagonist Sarah Hurlihy shows up to meet a blind date who happens to be her own father, "irresistible," Bankoff says. "The ensuing pages more than delivered on its promise of a fresh but knowing voice writing about male/female relationships with uncommon wit and lots of heart. I was hooked from the start." Over months and many revisions, Bankoff sent the manuscript out to 10 large publishers, had overnight offers from two and two more two days later.

"It was set to go to auction," recalls Cook, "when Pam Dorman, now my editor at Viking Penguin, put in a pre-empt, and teamed up with NAL, and editor Ellen Edwards, whose perspective is primarily mass market, so it was a hard/soft two-book deal from the beginning—really, really a wonderful deal Lisa engineered—that put me with amazingly talented people who could help me grow as an author." While at Bridge Works, Cook earned a tiny advance (and endured heavy editorial pressure, she admits reluctantly), with her big book deal she gained 400 times that amount and won an entire team devoted to supporting her—without, she hastens to add, telling her what to do. "I feel I've never in my whole life had a job where they just want me to be me!"

Editor Dorman confirms Viking's "major commitment" to Cook: "We fell in love with the strong, funny voice in Must Love Dogs, with the brilliant setup, and the sense that Claire had a real gift for the way families act together, and the way real people live and talk. There are a lot of suburban women out there who have seen themselves in Claire's books." Is the novel part of the "chick-lit" wave, featuring female protagonists "in flux" trying to orient themselves in jobs and relationships, as exemplified by the early British import Bridget Jones and the American lead for the fall, Jennifer Weiner's Little Earthquakes? Farrin Jacobs, associate editor at Red Dress Ink, which helped standardize "chick lit," thinks Cook represents an older version of the trend (sometimes called "hen lit" or "mum lit"): "Any breezy, late-coming-of-age novel with an endearingly flawed heroine, a kooky family and dating issues fits the category." Which isn't to say, Jacobs asserts, that the writing isn't serious or worthy of being reviewed. Cook, for her part, is unconcerned (like her agent) with where she fits among categories of chick lit, romance or "lite" fiction. She sees a "continuum of women" in her characters and tries to write for her "smartest and funniest friends to make them laugh despite themselves." She notes, "I think that people feel that my novel is well written, and these are valid subjects to write about. My audience is the women who finally can buy a hardcover—they have a little more time in their lives."

Must Love Dogs was a Barnes & Noble Discover Great New Writers pick, as well as a Book Sense selection, and though sales did not hit lofty projections (it never quite made the bestseller lists), the novel prevailed by sheer force of Cook's energetic, can-do personality. Viking sent Cook on tour, and she worked indefatigably a circuit of trade shows and bookseller functions. "Maybe coming into it at 45, you have a different perspective. I'm incredibly lucky and I try to earn it every day. Maybe some of what I'm bringing to this is what I've learned in other parts of my life." Earlier this year, she even managed to turn what might have been a disaster at an author appearance in Columbus, Ohio, into a memorable event, and got an invitation (along with Andy Borowitz and Andrew Hudgins) to judge the 2004 Thurber Prize for American Humor.

Cook is famous in the coastal town of Scituate, which appears in her novels variously as Marchbury and Rocky Point: people stop her as she walks down the street and hand her a book out of the window—"I'm the only novelist around, except for maybe a few mimeographing their own books. It's not a particularly artsy community." Everyone knows her, anyway, as a longtime teacher at the Montessori school, where she has taught all different ages and designed her own programs in dance and open-ocean rowing. Born in Alexandria, Va., Cook moved around with her big Irish family until settling in Scituate in grade school, when her father worked as a banker for the Boston Globe. Then her mother died suddenly, leaving five children; eventually, her father married again and had two more children. Cook and her husband, a land surveyor, resettled in Scituate to raise their own two kids, now 20 and 17. Must Love Dogs, featuring the tight-knit Hurlihy family, is a kind of tribute to the "larger-than-life Irish dad and the big families," Cook explains. "My whole area used to be called the Irish Riviera, and it used to have families like the Hurlihys, but people aren't having that many kids any more.

"I did such crazy things," Cook says of her zigzag work experience. "I did some advertising. I was continuity director for a suburban radio station"—which she draws on for the mother-daughter internship in Multiple Choice—"I joined the aerobics craze in the early '80s and ended up teaching classes in five towns with instructors working for me—I did Ethel Merman sessions and Beach Boys songs." At some point, she recognized the "frozen" state of her creativity, that she was "hiding" all those years—"I've met a lot of women who have these lifelong unrealized dreams and put everything into their families, you know, schlepping kids around and doing all this stuff, and even if you carve out the time, you're not getting to that big thing—when I think of it now, I think, how messed up was this? But I do wonder if I was just letting my stories collect. And all the detours I took? They're now the things that are making my fiction authentic and come alive."

Producer Gary David Goldberg (Spin City, Lou Grant, Family Ties) picked up a copy of Must Love Dogs because he had five dogs in the car and liked the cover, then contacted agent Bankoff for the movie rights. Warner Bros. has given the green light, and Goldberg will also be writing and directing the film, a big-budget romantic comedy to be released next year starring Diane Lane. Goldberg read Multiple Choice, as well, in an early draft, and though their lives "could not be more different," Cook recounts, he felt remarkably close to her portrayal of a harassed mother in midlife trying to go back to school with her surly freshman daughter: "Are you following my wife and me around?" he asked her.

"I just like to open my kitchen door and look out and write about the world that's right there," Cook says brightly. "I'm pulled into dialogue and characters. I don't like research. These are my stories."