My little boy is 3 weeks old and I'm reading this in sections as he reaches each age group.
There are lots of easy to follow guidlines which are definately having the desired effect on my baby. He is very calm and placid (currently asleep on my friend!) and both feeds and sleeps amazingly for his age. Everything that is in this book is obvious when you read it however, it had never previously occurred to me that the level of sensory input could have such a huge effect, ie. if he is fussing and upset and we know that it is not because he needs a feed, change or winding then, rather than trying to take his mind off it by jiggling, making faces at him, talking or singing to him, we just keep him calm and quiet - which does the trick!