I think you may be getting Montessori mixed up with Waldorf. Information on the montessori method is widely available (start here: http://en.wikipedia.org/wiki/Montessori, google for more). My son goes to a public Montessori school, and if I want access to the materials, I just ask the teacher. Everything is open, and parents (including prospective parents) are very much encouraged to observe the classroom.
Waldorf is kind of weird and secretive and expensive, and based on suspect and outdated science. http://en.wikipedia.org/wiki/Waldorf_education
No I meant Montessori. The Wikipedia article and the information on montessori.org provide a short description and a few example activities, but neither contain anywhere near enough insight/information to make a rational evaluation of the program. So far as I can tell you pretty much have to accept everything on faith.
Seriously, as much info about Montessori as you want is out there, and unless the school you're dealing with is a little shady, you should be able to walk in & request anything without paying tuition. You can also find a lot more than those two sites on the internet.
[1] With the exception of the original books from 90+ years ago.