DOMESTIC AFFAIRS Enduring the Pleasures of Motherhood and Family Life By Joyce Maynard Times Books. 313 pp. $17.95

TWENTY YEARS AGO, a pair of English doctors named Richard and Mary Gordon enunciated the two immutable principles of motherhood, which I have found useful in my own brief career as a parent: (1) Whatever you do is probably wrong. (2) Generally, it doesn't matter much anyway.

This is something mothers everywhere need to believe. From her very different vantage point -- rural New Hampshire in the '80s -- syndicated columnist Joyce Maynard documents her own experiences as a mother and wife with similarly reassuring good humor and optimism. For my money, books such as the Gordons' Practical Parenthood, Phyllis Theroux's recent Night Lights: Bedtime Stories for Parents in the Dark and, now, Joyce Maynard's delightful Domestic Affairs, are worth any number of tomes by the Spocks, Leaches and Brazeltons of the day, which often induce in the fledgling parent little but anxiety and guilt.

Not that Joyce Maynard is offering advice. Rather -- and this may be the point -- she is offering herself, in an unusually personal way, as a companion in experiences that we all go through and which are sometimes joyous, sometimes mind-threatening, but always drainingly intense. For the other critical thing mothers need to believe is that they are not alone. That's what friends are for, of course, but there's something singularly exciting about discovering companionship-in-adversity in print. I think every married woman I know will react to passages like this one (my favorite, and it's not just for mothers) with a chuckle of recognition. "Now," writes Maynard, "I'm seldom one to concede the commonly accepted notions of how men and women differ. (That men are more mechanically minded. Women are more sensitive. Men are more rational. Women are more emotional. I've known men and women who broke all of these stereotypes.) But there's one overwhelming and universal sex difference I'll grant you. Men take naps . . . Who ever heard of a woman stretched out in the middle of the day in a La-Z-Boy Lounger?"

Joyce Maynard is the woman who in 1972, as a precocious sophomore at Yale, bemused the public with a full-blown autobiography, quite unironically entitled Looking Back: A Chronicle of Growing Up Old in the Sixties. A decade later, after a brief stint reporting for The New York Times, marriage, a move back to the New Hampshire countryside and a baby, she published an accomplished, rather sexy novel called Baby Love (about how the former is so disruptively often a product of the latter).

Now, as Domestic Affairs in part records, Maynard is a mother of three who works out of her home -- with full-time babysitter in residence -- as a newspaper columnist and regular contributor to several national magazines. "In my newspaper days I wrote chiefly about isolated events and extraordinary phenomena. Now I document ordinary daily life." Domestic Affairs is, in fact, a collection of these inherently ephemeral pieces; yet, loosely organized into topics of such perennial interest as babysitting problems, family expansion, domestic finances, holiday celebrations, mess, flipping out ("the night Mom threw her beer"), childhood and maternal terrors, cutting the cord, and so on, the book somehow transcends the fragmentariness of its parts to offer a rounded self-portrait of a person about whom one wants unequivocally to say: This is a nice woman and a good mother and practically everything she has to say cheers, refreshes or gives pause. Go read her book.

Each reader will respond as her or his own preoccupations dictate. For me Domestic Affairs contains several memorable examples of its genre, besides the La-Z-Boy Lounger classic. Random highlights include:

Mom's problems or, as they are known about the house, MOM'S PROBLEMS. "I'm just a servant around here. Nobody appreciates me. Of course I'm mean and no fun to be around. I could have a pleasant personality too, if I got to sleep late and hang around watching cartoons every morning, and . . . take off any time I felt like it to go jogging. Just once, I'd like to see one of you put your bowl in the dishwasher without being asked . . ." etc.

The unremarked growth through the book of Maynard's youngest child, Willy, who sounds like a holy terror as an infant and toddler but who develops an irresistible personality of his own by the end, the kind of little boy who, having been "suspiciously quiet for half an hour, turns out to have pulled every one of approximately three hundred children's books off the shelves. 'Bookland!' he cries, as he brings me to come see."

Cutting Down the Tree. "I love holidays and Christmas most of all. I am always reminding Steve of that. Usually I'm in tears as I tell him." This one is required reading for all mothers out there who, like Maynard, are still "trying to grow up about Christmas."

Charlie's Birthday, or the time Mom postpones her 2-year-old's birthday party ("Where'd Charby's birthday go?") because of the pressure of other events, including the birth of a new baby, then learns a wonderful lesson in the art of celebrating simply from her own 6-year-old daughter.

The day Joyce Maynard spends with fellow New Hampshire working wife and mother, Christa McAuliffe, just before the start of astronaut training. "Steve McAuliffe, reading {his wife's} Teacher in Space application and saying 'Where is this woman? I want to marry her.' "

Directing the school play, with a cast of 94, a line for every child and a name for every character. And Jimmy, the school delinquent, who briefly becomes a star. "When I told Jimmy's mother how good {he} was, she looked at me incredulously. 'Jimmy?' she said. 'Jimmy?' The thing about a play is that when he's onstage Jimmy doesn't have to be Jimmy. He gets a fresh start. He's Mr. Paperclip. And people will clap for him."

Maynard herself quotes the letter she got from a married, but childless, male reader of her newspaper column " 'I've been reading stories about your family life every week now for a few months . . . And I wanted to tell you' (at this point I reached for my coffee, to better savor the compliment I thought I was about to receive) 'it was reading about your children that made me decide, once and for all, to get a vasectomy.' " Well, for every reader like that there are likely to be 99 others -- parents in particular -- for whom Joyce Maynard's essays will be a joy and a reaffirmation of the value of family life: "Sometimes at night the thought will strike me: There are three small people here, breathing sweetly in their beds, whose lives are for the moment in our hands. I might as well be at the controls of a moon shot, the mission is so grave and vast." :: Elizabeth Ward, author of "David Jones: Mythmaker," is the mother of three children.