I'm readint the book "Montessori from the start" and trying to apply Montessori at home with my 18month old. I'm facing some challenge doing it on my own, how to apply certain concepts and also having some questions on how to do certain things practically. Where can I go to get some help? Who can I talk to?
http://whatdidwedoallday.blogspot.com/ has links to dozens of Montessori homeschooling blogs sorted by 0-3, 3-6, etc.
There's also an ongoing Montessori at home thread in this forum.
You can also just post questions here.
Do note that that particular book has some absurd ideas about independence in infants and toddlers that have nothing to do either with appropriate child development or Maria Montessori's work. So definitely pick and choose from what works for you and makes sense for your family.
Lisa Nolan has online Montessori curricula for various age groups. There is a charge, but it might give you some ideas. 18 months doesn't necessarily need a "curriculum," rather more just lifestyle philosophies and activities to meet developmental stages, I would think, but this site offers some interesting ideas.
There are many wonderful Montessori Mamas on MDC so definitely post here with specific questions! I love the Michael Olaf catalogs for descriptions of theory and materials for the youngest child: The Joyful Child and for 6+: Child of the World http://www.michaelolaf.net/ Also Aline Wolf's work is very accessible: http://www.parentchildpress.com/awolf.php The AMI website has very nice articles online and also if you get a membership, their periodicals are great. Good Luck!