The National Lampoon and Sesame Street. Christopher Cerf sees no inconsistency in being involved in extremes.

"They are different ways of being a kid," he says. "A responsible kid."

"I grew up in a pun-loving family," writes Cerf in his latest project, "Kids -- Day In and Day Out," (Simon & Schuster, $7.95). Edited with Elisabeth L. Scharlatt, the book is a rambling 530-page manual covering everything from toys to toilet training. It has been called a cross between Studs Terkel and Hints From Heloise.

Over a six-year period Cerf and Scharlatt distilled 10,000 pages of advice from over 500 people. Since the premise of the book is that parents are the real experts in child-rearing, most of the contributors are parents or children. Their anecdotes were collected by questionnaire and include those from both the famous and the not-so-famous.

Anne Byrne Hoffman writes about keeping "your creativity in check" when it comes to children's clothes: "My mother had her own ideas about style, and for a 9-year-old, that was just plain bad news." Husband Dustin took some of the book's photos.

Margaret Mead wrote on day care: ". . . The ideal situation is to have groups of people of different ages live close enough together so that young children can be cared for within the extended neighborhood, rather than in institutions."

Franz Kafka, in a letter to his father, is quoted on discipline: "Please Father, understand me correctly . . . in themselves, they (disciplinary measures) only became depressing for me because you, so tremendously the authoritative man, did not keep the commandments you imposed on me."

"Kafka did not fill out a questionnaire," says Cerf, 38, a short energetic man with a rapid-fire meld of lines both serious and funny. Like his father, Bennett Cerf, the late Random House publisher, humorist and "What's My Line?" panelist, his face is saved from being owlish by a perpetual grin.

Some of Cerf's favorite selections were submitted by his mother, Phyllis Cerf Wagner (now married to ex-New York City Mayor Robert Wagner) and his younger brother Jonathon, who has written a Sesame Steet book. Under the chapter, "Books," his mother, creator of the Beginner Books series, for which Dr. Seuss is the most famous contributor, writes, "I never stopped pointing out to my kids how miraculous reading is . . . "

All of the Cerfs were voracious readers and Christopher's specialty was science fiction. "It was just about the only field of literature," he writes, "in which my father wasn't an expert. What a thrill it was to find him a new story that he would read and love, rather than the other way around."

"It was not only that my father was a publisher," he said during a stop in Washington. "but that he loved publishing. . .

"I don't care if you go into publishing." his father once said, "but if you don't, I'll kill you."

Rather than being ponderously serious, the Cerfs had a certain wacky, eccentric humor typified by the Christmas Ritual of the Rubber Snake, retold in "Kids" by Christopher. "The basic idea is for the donor to wrap the snake in such a way that the recipient opens it without suspicion."

Over the years the snake has been passed off wrapped as a hockey stick, disguised as a gift from a distant relative (complete with forged card) and as a table favor at somebody else's dinner party.

While other families drink eggnog and decorate the tree, the Ritual of the Rubber Snake continues as a 30-year Cerf family tradition.

The Cerfs instilled an appreciation of what "Christopher Cerf calls the "silly things" and many examples are included in "Kids."

There's the New York mother who tried to persuade her daughter to brush her teeth by telling her the tooth fairy works on consignment, paying dimes for damaged merchandise and a whole dollar for teeth without cavities.

And the letter from Cerf's then 7-year-old brother to their Uncle Herbert. "I'm sorry I didn't thank you for my Christmas present and it would serve me right if you forgot my birthday next Thursday."

Also reproduced in "Kids" is a piece of unsolicited advice on child rearing from playwright Moss Hart. In a letter to Bennet Cerf, Hart recommended "the Klobber Method."

Prof. Ernest J. Klobber, the father of six untamed children, was about to be carted off to a sanitarium in a state of nervous collapse when he was kicked by one of his kids. Heavily sedated, he responded reflexively with a "klobber" on the child's head.

"It is the greatest invention since the wheel," wrote Hart, "and as your wife seems to object to it, try it on her first instead of the children and let me know the results."

Bennett and Phyllis Cerf did not take Moss Hart's advice. "They never spanked us and for that I am grateful," says Christopher Cerf.

Cerf, dispenser of anecdotes and advice on child-rearing, and his wife, Genevieve, have no children. "I think my wife and I will have them . . . eventually."

In the meantime, the self-proclaimed "responsible kid," has hopscotched to another project, "A History of the 80's," a satire of the Time-Life decade books. Publication date -- Jan. 10, 1980.

In the next 10 years Cerf predicts that print will be replaced by the Universal Literacy Code, similar to the Universal Pricing Code; there will be a legislative crime wave and Washingtonians will be afraid to walk past the Capitol for fear of being mugged by a congressman; and the Great Wall of China will tour the United States.