I’d definitely start with the most practical ones, and these two are my very favorite, written by two of my Montessori mentors.
Come sono diventata una mamma Montessori e ho trovato la felicità, Cristina Tébar (Italian). Spanish version: Montessori En Casa, el cambio empieza en tu familia
The Montessori Toddler, Simone Davies (English)
This is a list of books for parents, but I want to include this children book (written by one of my favorite Spanish Montessori voices), because it’s beautiful and very educating also (mostly?) for parents. At the moment it’s only in Spanish:
Cuentos Montessori para crecer felices, Marta Prada (Spanish)
And here’s the classic list of Montessori books, starting by the ones written by Maria Montessori herself (a bit more complicated, but worth reading):
The Absorbent Mind, Maria Montessori
Secret of Childhood, Maria montessori
Discovery of the Child, Maria Montessori
The Montessori Method, Maria Montessori
Maria Montessori’s Own Handbook: A Short Guide to Her Ideas and Materials, Maria Montessori
Montessori From the Start, Paula Polk Lillard
The Joyful Child: Montessori, Global Wisdom for Birth to Three, Susan M. Stephenson
Child of the World: Montessori, Global Education for Age 3-12+, Susan M. Stephenson
Montessori Learning in the 21st Century: A Guide for Parents & Teachers, M Shannon Helfrich
Montessori Read & Write: A parent’s guide to literacy for children, Lynne Lawrence
How to Raise an Amazing Child the Montessori Way, Tim Seldin