Today I was thinking about suggesting books.
For preschool, which is age group 3-6, there is
For understanding the philosophy behind the method
Montessori Today: A Comprehensive Approach to Education from Birth to Adulthood by Paula Polk Lillard
Teaching Montessori In The Home The Pre School Years by Elizabeth Hainstock
Basic Montessori: Learning Activities For Under-Fives by David Gettman
With those 3 books you pretty much have a good idea about how to present and have a good start. They also help by telling you how to make your own material eventhough sometimes it can be something that takes up a lot of time.
Then when you get to the elementary grades, age group 6-9 and 9-12 Those books are a must.
The advanced Montessori method-1, and method II
Pour une version française de ces volumes, ce livre est pour l'éducation au primaire.
Il y a Pédagogie scientifique, t. 02 [nouvelle édition] by Maria Montessori
Il y en a un pour le préscolaire, mais je ne l'ai pas lu. C'est la pédagogie scientifique t.01.
That's all I can thing of for now, hope it can help you out.