The Joyful Child
If you are interested in the Montessori method I highly recommend The Joyful Child. It explains how Dr. Maria Montessori first started in her approach to learning along with why implementing it in the first three years of life is so crucial. It also helps by explaining Dr. Maria Montessori's thinking when she started doing certain things. If you have any questions about the Montessori philosophy, this book will answer them!
The School Years
If you are already homeschooling a child in the elementary school age and you want to add a Montessori approach to your teaching style, this is the book for you. Teaching Montessori in the Home: The School Years is wonderful because it explains the various math and language activities Montessori students of this age do. Want another reason to buy this book? It includes instructions for making all the materials yourself so you don't have to spend a lot of money at once. Basically, it's the handbook for Montessori-style homeschooling!
The Pre-School Years
What to do when your baby starts exploring your house? Wonder no more, because this book has the answers! Even if you're unsure about the Montessori method, the activities and ideas presented in this book will work for you. They will allow you to entertain your little one while helping his or her brain develop and maximize its potential. And again, it includes instructions for making the materials yourself. This means you save money!