To a new parent, all children's books may look the same. It's partly true - all mediocre children's books do tend to look the same. It is the finer examples , the books with rich, inventive illustrations and a colorful text, that will capture the imagination and hearts of both parent and child.
According to Betsy Hearne, an educator and author of ''Choosing Books for Children'' (New York: Dell, $2.95.), if youm enjoy the book, the children will soak it up.
When paging through a children's book, she advises asking yourself a simple but important question: ''Is it clever or boring?'' A dull text will bore a child as much as it will an adult. If the illustrations appeal to you at a first glance, take a second look slowly and carefully the way a child will.
Good children's book illustrators get right to the heart of the story and make it come alive. When examining the pictures, parents should note whether they are ''finely detailed or frantically cluttered, nicely simple or crudely unskilled, absorbing or dull, strong or heavy handed,'' she writes.
Expressive characters and illustrations depicting action are especially important in picture books, Mrs. Hearne believes. Still, pretty scenes are sometimes lost on children.
In terms of the story line, good intentions do not always make a good book. ''Sweet and preachy is a nauseating combination,'' writes Mrs. Hearne, and any moral to the story should be well hidden, or children will wriggle away.
According to Mrs. Hearne, the text of a successful read-aloud book must be pithier and developed more actively than an adult short story. The words should sound smooth and natural, not stiff or needlessly repetitive.
She points out that the finest children's authors use choice words without worrying whether children can understand them. Even the youngest children often understand much more than adults give them credit for, especially in the context of a story.
While children's reading abilities and comprehension levels vary widely even within the same age, here is a rough guideline of books appropriate for various age levels, as outlined in ''Choosing Books for Children'':
* Ages 2-6: Choose picture books with illustrations on every page and very little text. These books are meant to be read aloud, and the illustrations should be interesting enough to satisfy a child's close scrutiny.
* Ages 7-9: Beginning-to-read books have short episodic chapters, scattered illustrations, simple vocabulary, slightly enlarged type, and an uncomplicated story line.
* Ages 10-13: Children in this age group can handle a wide range of fiction: comedy, tragedy, romance, adventure, fantasy, and realism. These books look like a short novel.
Betty Hearne emphasizes that children of all ages have strong feelings and are cheated by books that are flat, emotionless, and dull.
James Trelease, a read-aloud book advocate, agrees: ''When you ask a person to name his favorite book or movie, it is usually one that has touched his emotions. Children want the same thing in their books.''