R.J.
<grinning> There was a similar Q just yesterday... So I hope you don't mind but I'm going to cut and paste :)
http://groups.yahoo.com/group/playschool6/ is a Montessori Homeschool Message Board on yahoo groups that's really amazing. They do MM homeschool across the age spectrum, but there's also another sistergroup specific to preschool aged kids... but I'm not on that board, so I don't have the address.
Another worth checking out is MontessoriMakers http://groups.yahoo.com/group/montessorimakers/ which is specific to making your own MM materials.
Both groups have been extraordinarily helpful in my own journey. :) :) :)
Both are also moderated... so if you don't have one already, you would need a YahooID (free), and then it takes up to about a day to recieve approval to join.
My favorite Montessori HS Resources:
http://jojoebi.blogspot.com/2009/07/montessori-links.html
http://www.blog.montessoriforeveryone.com/the-ultimate-po...
http://www.montessoriforeveryone.com/
http://www.montessorimaterials.org/index.html
http://www.freemontessori.org/
http://www.nienhuis.com/index.php
http://www.montessorird.com/index2.php?cPath=1&osCsid...
So too, if you like Maria Montessori... you'll also probably really like Charlotte Mason. (We do a 40/40 split between MM & CM in our house, with the remaining 20% being wildly eclectic). Here's some more info:
http://simplycharlottemason.com/basics/what-is-the-charlo...
http://simplycharlottemason.com/basics/started/charlotte-...
http://www.amblesideonline.org/
http://groups.yahoo.com/group/SecularCM/ (there are religious CM groups... but as we're secular -CM is simplicity to secularize- this is the group I know best)
Cheers!
R