I'm not an expert, but Dr. Jay Wile is... hear what he has to say about this book:

Review by Dr. Jay L. Wile, Apologia Educational Ministries, Inc.

“This is an invaluable resource to anyone who wants to learn how to create a serious science fair project. It is also a great resource for those who would like to organize a science fair for their local homeschool group.  Mrs. Gerwitz has done a remarkable job of gathering all of the information that you need and putting it into
one easy-to-read book.

In this book, you will learn the general guidelines for preparing science fair projects, how to choose a topic for your project, how to make your project stand out amongst other projects, and how to record your endeavors.  There are many helpful ideas in this book, including stories of science fair project failures from which you
can learn. In addition, there are tables that include valuable helps such as a schedule for your science fair project, a checklist, a list of rules and guidelines, and (most importantly) a long list of both print and online resources to help you come up with ideas for your project.

This book is not only for students, however. If you are a parent trying to start a science fair for your local homeschool group, this book tells you what you need to know.  There is a 15-point summary that lists all of the things you need to do to get a science fair started, a flowchart to keep you on track, and a series of tables that list the judging criteria. If you want to create a winning science fair project or start a science fair in your area, I recommend that you start with this book.”