I used this book with my three boys, 4th-7th grades, as part of our homeschool Bible curriculum. I liked how it really dug into The Word. I had just studied through James in the summer, so it was so enlightening to go through this with them and learn even more.
I agree that 3rd grade may be almost too young for this book, depending on the child and the setting. I believe it is appropriate to go up into teens if they don't mind the younger aged aim. The content is pretty deep, but written as though it is a story or experience for middle schoolers.
The study is set up to do 5 lessons per week, but you could do it in a different way if you want. Each "day" varies in length depending on the activities and reading. My kids enjoyed working in this study, and we have started Genesis 3-11 and it is amazing too!
I bought this book to study with my Sunday School children. There is a lot of "meat" in this book. The teachers were enlightened as well as the children. Out of the 3 books we've studied in the Discover4Yourself series, this is my favorite so far. As a matter of fact, because of its richness in the Word, our teenagers are doing it now and learning so much about how to live God's Word. I highly recommend this book!
This book is a wonderful and fun way to teach student about bible truths. My students love bible class, because of the fun way the book goes about teaching the subject in a easy to understand language.