CHILDREN, THE PERPETUAL thespians and makebelievers, seem to enjoy Halloween more than any other holiday. October 31st is the day they throw on new identities and give in to the pleasures of terrifying their friends and being frightened in return. The season of witches and ghosts has been fertile territory for children's books, and this fall several, ranging from a how-to book to a collection of verse, deserve special mention. Figuring prominently in two of them is the symbol of Halloween -- the pumpkin.

Every aspect of the pumpkin, from seedling to pie, is covered in the All-Around Pumpkin Book, by Margery Cuyler, illustrated by Corbett Jones (Holt, Rinehart and Winston, $8.95, paperback, $3.95. Ages 6-12). Did you know, for instance, that if you grow your own (and Cuyler covers the whole process, including the proper mulch), you can help them reach huge proportions by making a slit in the vine about three inches from the pumpkin when it's just cantaloupe-size? Into the slit, insert a 6-inch piece of lamp or candle wick. Place the other end of the wick into a small bowl of sugar water or milk, and keep refilling. The pumpkin will reach state-fair-competition size.

The Mystery of the Flying Orange Pumpkin, written and illustrated by Steven Kellogg (Dial, $5.95. Ages 3-7), is about a jack-o'-lantern-to-be, happily growing in a garden. Some weeks after the pumpkin's successful germination, the property is sold to a terrible scrooge of a man, Mr. Klug. When Klug refuses to let the children who have been tending "Patterson Pumpkin," as they call it, reap their harvest, they devise an ingenious way of spiriting Patterson away. Kellogg's slightly round, rumpled figures are appealing and his scenes are drawn with telling detail (the curmudgeonly neighbor reads "The Daily Complaint" with a sour look on his face). This warm and clever story would make even a goblin smile.

That Terrible Halloween Night, by James Stevenson (Greenwillow, $7.95. Ages 4-8), is not only about pumpkins, monsters, and being scared on Halloween. It's about grandparents and their spell over young children. In Stevenson's book, Louie and Mary Ann plan to frighten their grandfather because, after all, it's Halloween and he isn't taking proper notice of the fact. First they put a mask on Leonard the dog and send him into the living room to frighten Grandpa, who is reading the paper. When that doesn't work, they resort to costuming themselves. Not only does Grandpa remain unperturbed, he turns the tables on them and tells such a scary story they end up huddling in his lap, he looking very pleased of course to have them there.

Stevenson, as always, manages to convey an entire world -- its style, its atmosphere, and the emotions of its inhabitants -- through a few strokes of his pen. The expressions and postures of what are essentially simple figures characterize them completely.

The story that True Kelley and Steven Lindblom tell in The Mouses' Terrible Halloween (Lothrop, Lee and Shepard, $6.95. Ages 6-9) is wonderfully zany. It's just the kid of wild mixture of humor and implausible episode (at one point mice from outer space arrive in a pumpkin-shaped flying saucer) that children love. The array of costumes illustrated here at the various Halloween parties attended by the Mouse family will delight children. But, alas, the lack of color (only washed-out shades of purple and orange are used) will not.

In the Witch's Kitchen: Poems for Halloween, compiled by John E. Brewton, Lorraine A. Blackburn and George M. Blackburn III and illustrated by Harriet Barton (Crowell, $8.95. Ages 3-8) includes verse by Shel Silverstein, John Ciardi and 24 other poets. But one of the book's most charming inclusions is by an unknown author: Three little ghostesses, Sitting on postesses, Eating buttered toastesses, Greasing their fistesses, Up to their wristesses, Oh, what beastesses To make such feastesses!

Its whimsy is typical of this volume, which seems to have been collected on the premise that frightening children is unhealthy. Perhaps it is; certainly this volume conveys a benign impression of Halloween. It makes for good bedtime reading. At the end, everyone is guaranteed to fall asleep, untroubled by nightmares.