Everything below is placed in its category based on when I found it, not in any other meaningful order! I'll be keeping it that way so new additions will always be at the end of the appropriate list.
From Childhood to Adolescence by Maria Montessori. Excerpts can be found here.
Schools with Adolescent Programs
Montessori Adolescent Academy
E. C. Montessori and Grade School
Peace Montessori School "The Adolescent curriculum is “society” and relates to the needs of the particular community."
Denver Montessori Jr/Sr High School
Childpeace Montessori School - excellent curriculum ideas
Hershey Montessori School - has a long-running, highly acclaimed adolescent program. Has sections entitiled Academic Areas and Personal Growth
Damariscotta Montessori School - some great info on program components
Omni Montessori School - has some very good information about curriculum
Sky Valley Montessori
Montessori School of Lake Forest - brief syllabus provided
The Montessori School of the Berkshires
Montessori School of the Mahoning Valley
The Maria Montessori School
Mountain View Montessori School
Montessori Borealis Public School - some good, albeit brief, curriculum information
Downtown Montessori Academy
Joliet Montessori School - has a link to the students' hydroponics business!
Templestowe College Erdkinder Stream
Kawartha Montessori School
Oak Knoll Kinderhaus Montessori
Community Montessori School
Green Valley School - the jr. high tour page; has links to their daily schedule, jr. high Montessori principles, curriculum and more
Austin Montessori School - this is Donna Bryan Goertz's school (author of Children Who Are Not Yet Peaceful--awesome, awesome book!). Doesn't say a whole lot about the adolescent community, but the site has a lot of good stuff, like the Adolescent Community's Reading List
Articles About Montessori and Adolescence
Erdkinder - The Montessori Answer to Adolescence
Adolescent - From Community to Society
The Montessori Adolescent - A Brief Overview
Montessori Muddle - has some different posts about adolescents, including things like changes in sleep cycle. There is actually a whole bunch of cool educational stuff there not restricted to working with adolescents!
Special Needs of Adolescents from Montessori Secondary Education Centre
Adolescent Truths for MMUN - Interesting perspectives and ideas.
Washington Montessori's Middle School Teacher Training; the Handbook is very worth reading and has the courses' reading lists
Montessori Teacher Institute - summer 2013 training
Misc. Adolescent Links
Australian Montessori Teacher Education Foundation
Tomorrow's Child - absolutely fantastic pdf all about Montessori jr/high school
Adolescent Practitioner - a site with groups, useful quotes. Not much there, but what's there is useful.
AMI Montessori Orientation to Adolescent Studies brochure - this is a brochure to inform people who are interested in taking the adolescent training program; the information within is just amazing!