The book is great for young kids. It is the only Sudoku book that I know of that has solely simple 4x4 puzzles. Although the puzzles are categorized as Easy, Medium, and Difficult, most of them are simple and easy to solve. Smart 4-year olds have solved many of the puzzles in the book. Children of 6 years of age solved most of the puzzles while 8-year olds can solve all the puzzles.
I strongly recommend this book for children as well as adults. One distinct feature of the book is the variety of Sudoku puzzles that are included. It even contains Sudoku puzzles with pictures of animals - dogs, cats, and fish.