I stumbled upon this post today at Starry Sky Ranch. Midway through the post, the author mentions a book called A Montessori Mother by Dorothy Canfield Fisher, which was written in 1912. It's out of print, but I was thrilled to find the book in its entirety (library card pockets and all) through Google Book Search.
After a quick perusal, I find I can't "put it down" (what's the equivalent expression when you're reading a book online?). The author gives very detailed descriptions of a day she spent in one of Maria Montessori's Casas, and I find it fascinating. I hope you enjoy it too!