Picture books for childrenThe Wild Swans, by Hans Christian Andersen, retold by Naomi Lewis. Illustrated by Angela Barrett. New York: Peter Bedrick Books. Pages unnumbered. $11.95.

The Winter Wren, written and illustrated by Brock Cole. New York: Farrar, Straus & Giroux Inc. Pages unnumbered. $12.95. Moses the Kitten, by James Herriot. Illustrated by Peter Barrett. New York: St. Martin's Press. Pages unnumbered. $9.95. A Year of Birds, written and illustrated by Ashley Wolff. New York: Dodd, Mead & Co. Pages unnumbered. $10.95. The relationship between art and text in children's picture books is delicate. The illustrations must expand the reader's visual knowledge of the story without overpowering the writer's prose. If a sense of balance is achieved, the illustrations will enhance the text and be remembered long after the words have been forgotten.

This new edition of Hans Christian Andersen's The Wild Swans is beautifully retold by Naomi Lewis, a distinguished English writer and critic.

In a faraway land, a king was proud father to 11 sons and one daughter, Elisa. The family lived happily together until the king married a beautiful but evil queen.

The children's new stepmother doesn't like the princes and princess. As soon as she can, she sends Elisa to live with a peasant family in the forest, and she banishes the 11 sons from the kingdom and casts a spell on them that turns them into swans.

When Elisa is 15, she is sent back to the palace, but she is so beautiful that the stepmother again banishes the princess into the forest. While sleeping in the forest, Elisa dreams of her brothers, and she decides to go in search of them. When she finds them, she learns about their hardships. The fairy Morgana tells Elisa how to break the spell cast by the stepmother.

Angela Barrett's delicately detailed illustrations convincingly portray a ''faraway'' land. The gentleness of Elisa and ber brothers is reflected in the soft greens used in the illustrations, but the darker reds and browns give the pictures substance and depth.

''One year spring would not come. The new wheat turned yellow and rotted in the furrows, and in the air was a taste of iron.'' So begins author-illustrator Brock Cole's touching tale, The Winter Wren.

Simon, a young peasant boy, learns that Spring is asleep at Winter's farm and is unable to wake up. When Simon's mother tells him that Spring is a princess dressed in green and gold, Simon takes his younger sister, Meg, with him and goes to Winter's farm to wake up Spring.

But it isn't as easy to awaken Spring as Simon thought - Winter turns Meg into a tiny brown winter wren. Dismayed, Simon sits down and cries. But with the help of the winter wren Simon defeats Winter. When Winter sows sleet, Simon spreads meal from his sack and wheat springs up. When Winter prunes the buds from his apple trees, Simon throws his apple into the orchard and the apples trees become laden with fruit.

Simon does find Spring, and he does wake her up. But the villagers and Simon's mother don't believe it's Simon and Meg who bring Spring back to the village.

The dark browns of Mr. Cole's beautiful watercolor illustrations enchance the simpleness of the village peasants and Simon, and the gradual introduction of Spring green makes the illustrations come alive with color.

The joy and beauty of James Herriot's stories about life as a Yorkshire veterinarian have placed him among the most popular of storytellers. Although his books have been aimed at an adult audience, his stories appeal to readers of all ages. His latest, Moses the Kitten, is written especially for children. Here, as in his other works, Mr. Herriot's enjoyment of, and wonder at, animals shine through.

While driving to a farm on a biting winter day, Mr. Herriot sees a small black bundle of fur curled up into a little ball. Walking over to it, he expects the tiny animal to be dead. But much to his surprise, the kitten is alive. Mr. Herriot takes the kitten to the farmhouse with him, and the farmer's wife pops the little cat into the fireside oven on the large kitchen range.

Moses, so named because he was found among the rushes next to the pond, survives. He not only finds a warm place to live in the barn, but he becomes a favorite with the farmer and his wife.

Peter Barrett's sensitive illustrations capture the beauty of the Yorkshire moors and their people, as well as James Herriot's love for the life he leads.

A Year of Birds is a warm, joyful book about the various kinds of birds that visit Ellie's house each month of the year. The linoleum block prints are bold and simple, yet each illustration is filled with details about Ellie's life.

As the months pass by, the seasons change and new birds visit her home each month. But the illustrations not only show the various seasons and birds, they also tell the story of a loving, growing family.

The integration of simple text and bold illustrations in this book will capture the imagination of adults and children alike.