Hi. My name is Lynda Madaras. I write books about growing up. I get tons of letters from boys. They tell me just what they're thinking. They ask questions. Many of the things they say are here in this book. Many of their questions are here, too, along with my answers. So boys like you helped to write this book.

In her uniquely warm and funny style, Lynda Madaras wrote this entirely new book especially for younger boys to give them everything they need to know about the new and exciting changes that are happening to their bodies during puberty.

Illustrated with fresh and funny cartoons, On Your Mark, Get Set, Grow! is the seventh book in the popular "What's Happening to My Body?" series of growing-up books for boys and girls. Praised by parents, teachers, nurses, doctors, and especially kids, the bestselling "What's Happening to My Body?" books for older boys and girls are on the "Best Books for Young Adults" list from the American Library Association and have been translated into 12 languages. Over 2 million copies of the "What's Happening to My Body?" series are in print.