Sand Cake, by Frank Asch (Parents' Magazine, $4.95), provides an exercise for the imagination, as a boy bear and his father "bake" and "eat" a make-believe pastry. Asch, as usual, goes for droll, simple lines and bright colors. (Ages 4-8)

Summer at the Sea, by Eleanor Schick (Greenwillow Read-alone/-Morrow, $5.95), with hazy-sky-colored pictures, evokes the sights, sounds and smells of a family stay at a comfortable beach cottage. (Ages 5-8)

Camp KeeWee's Secret Weapon, by Janet Schulman, illustrated by Marylin Hafner (Greenwillow Read-alone/Morrow, $5.95), follows a soft-ball-loving girl to camp where, after a false start, she becomes the star of her cabin's team. The illustrations have an agreeable cartoon-like quality. (Ages 5-8)

Noises in the Woods, by Judi Friedman, illustrated by John Hamberger (Fat Cat/Dutton, $5.95). For those planning mountain hikes or stays at lakeside cabins, Friedman gently directs attention towards owls, crickets, rabbits, frogs, deer, telling how best to observe those creatures who share our habitat. A well drawn book, it imparts a flavor of the sylvan environment, as well as a sense of wonder about discovering heretofore "unheard" noises. (Ages 5-8)

Travel Games (Cinnamon House/Grosset & Dunlap, paperback $.95) is for kids who can read (and write). It's a handy size, useful for tucking in a tote-bag or glove compartment. While heavy on statename activities, it also offers crosswords and variations on basic word games. (Ages 8-up)

During Water Peaches, by Laurel Trivelpiece (Lippincott, $7.95). Set in the fruit-growing valley of California just after the onset of World War II, this is an impressive first novel by a poet and short-storey writer. The heroine, LaVerne Honeycutt, has secured her first real job in a government office set up to oversee the crews of Mexican laborers brought across the border to pick the crops. Eager, intelligent, ferociously determined to secure a college education against all odds, she herself is the daughter of Okies who look down on the Chicanos and yet regard LaVerne with hostility for wanting to better herself. She is torn between loyalties: to her down-at-the-heels family; to her boss, a middle-class Spaniard who decides his own allegiance must be to the oppressed workers and so sets out to organize them, becoming a fugitive in the process, and to the arrogant, aristocratic Mexican boy who regards it as a game to try and seduce her. As is so often the case in such fiction, sorting out all of these demands enables LaVerne to grow up, to mature like a perfect "water peach," and to face the future with new-found self-respect. (Ages 12-up)