This book was, by far, the most helpful book I have read in this area. I have read and reread this book many times with my first and second child, and still seem to find new information which is helpful. Both of my children are excellent sleepers, in spite of my second child having severe colic, and I truly owe a great deal of it to this book. I now understand children's sleep cycles and their development of sleep. I also have a better understanding of the importance of healthy sleep habits early on and of napping. I have been told many times I was lucky to have two happy babies, but honestly, they were happy because they were well rested.