A guide for young writers; In Your Own Words, by Sylvia Cassedy. New York: Doubleday. $7.95.

"At every moment in your life there is an event taking place that is important enough to be put down in words." Sylvia Cassedy firmly believes this and encourages aspiring young writers to take pen in hand. Her book, subtitled "A Beginner's Guide to Writing," urges young people 9 and older to observe the world within them as well as the world around them and to use their senses fully.

This guide, which is enjoyable as well as highly informative, deals with a wide variety of prose and poetry. Prose chapters include such topics as myths, hero tales, fairy tales, ghost stories, science fiction, essays, school reports, book reports, and letters. The poetry section examines emotions and imagery at length, with examples of traditional forms, haiku, riddle poems, and rhythmic verse. Poets represented include both the well-known and children of various ages.

Sylvia Cassedy, who is an experienced teacher of writing, has furnished a valuable book of advice and assistance for would-be writers. Teachers of writing will also find this guide worth examining.