This is not a comprehensive list, certainly, nor do I necessarily endorse all of the sites listed, but as I come across sites that may be of interest I will add them here. Finally, as of 5/24/2011 started to organize by category. Work in progress…
Theravada
- Abhayagiri Buddhist Monastery – Teachings, Books & Print
- Access to Insight (Suttas, books, articles, and more)
- Ajahn Chah: The Teachings of
- Amaravati Buddhist Monastery Publications
- Aruno-Teachings from Aruna Ratanagiri
- Barre Center for Buddhist Studies
- Buddha-Dhamma Buddhadasa Archives
- BuddhaSasana (compilation of articles in English, also available in Vietnamese, primarily from the Theravadan tradition)
- Buddhist Publication Society Online Library
- Dhamma Web (teachings in the Vipassana tradition, majority of the resources in Burmese but also English)
- Forest Dhamma Books (free for download)
- Forest Meditation: A Theravadin Buddhist Website
- Forest Sangha: A portal page to the Buddhist communities associated with Ajahn Chah
- Godwin Samararatne
- Insight Meditation Center
- Krishnamurti Vipassana Meditation (Indonesia)
- Metta Programs – Insight Dialogue (Gregory Kramer)
- Santipada: Buddhism as if life matters (Bhante Sujato)
- Sati Center for Buddhist Studies
- Sayadaw U Tejaniya
- Seattle Insight Meditation Society (Rodney Smith)
- Vipassana Dhura Meditation Society (English, Thai, Spanish, Croatian)
- Theravada Dhamma (German, English)
- The Vipassanā Fellowship (teachings from Ayya Khema, Bhikkhu Bodhi, Bhante Gunaratana, and others)
- What the Buddha Taught (multi-lingual site with teachings from Buddhadasa Bhikkhu, Ajahn Mun, Thanissaro Bhikkhu and others)
Zen/Ch’an
- Boundless Way Zen
- Crooked Cucumber (Shunryu Suzuki)
- David Loy
- Deep Streams Zen Institute (Joseph Bobrow)
- Dharma Drum and Dharma Drum Mountain (Master Sheng-Yen)
- Dharma Field (Steve Hagen)
- Everyday Zen (Norman Fischer)
- Kwan Um School of Zen (Master Seung Sahn)
- Mountains and Rivers Order (John Daido Loori)
- Ordinary Mind (Barry Magid)
- Pacific Zen Institute (John Tarrant)
- San Diego Zen Center
- Sweeping Zen
- Tarrant Works
- The Village Zendo (Pat Enkyo O’Hara)
- Zen Peacemakers
- The Zen Site
Vajrayana
- The Berzin Archives (Mahayana/Vajrayana, including glossary of Tibetan terms)
- Blazing Splendor
- The Chronicle Project
- Dharma Ocean Foundation (Reggie Ray)
- Dzogchen Ponlop Rinpoche
- Lama Yeshe Wisdom Archive
- Mangala Shri Buti (Dzigar Kongtrul Rinpoche)
- The Power of an Open Question (Elizabeth Mattis-Namgyel)
- Siddharta’s Intent (Dzongsar Kyentse Rinpoche)
- Tergar International (Yongey Mingyur Rinpoche)
- Unfettered Mind: Pragmatic Buddhism (Ken McLeod)
- View on Buddhism (Tibetan) Buddhist practice and philosophy (English, Polish, German)
“Secular” Buddhism
- Secular Buddhism
- The Secular Buddhist Association (podcast and more)
- The Skillful Meditation Project (Jason Siff)
- Stephen and Martine Batchelor
Other Non-Sectarian Teachers of Interest
- J. Krishnamurti
- Toni Packer
- Vimala Thakar (in French, English and Dutch to come)
Appealing to the Younger Generation
- Against the Stream Buddhist Meditation Society (Noah Levine)
- Buddhist Geeks
- D.I.Y. Dharma
- The Interdependence Project
Women and Buddhism
- Alliance for Bhikkhunis
- Anenja Vihara (German)
- Aranya Bodhi
- Awakening Truth
- The Bodhi House
- Carolina Buddhist Vihara
- Dhammananda Bhikkhuni
- Fourfold Sangha
- Monasteries for Bhikkhunis in Sri Lanka
- Sakyadhita
- Sanghamittarama
- Santi Forest Monastery
- Saranaloka Foundation
- Sati Sariniya Hermitage
- Sravasti Abbey
- Sujato’s Blog
- Support Network for Women Renunciants in Malaysia and Singapore
- Thai Bhikkhunis (Thai)
Buddhism, Chaplaincy and Palliative Care
- Amitabha Hospice (NZ)
- BuddhistChaplains.org
- Buddhist Hospice Trust (UK)
- New York Zen Center for Contemplative Care
- Metta Institute
- Sati Center for Buddhist Studies – Chaplaincy Training
- Upaya Zen Center
- Zen Hospice
Addiction, Recovery and Buddhism
- Addiction << Digital Dharma
- Against the Stream Buddhist Meditation Society
- Fifth-Precept (UK)
- Heather Sundberg
- Joan Tollifson on Addiction and Free Will (article and reference)
- Judith Ragir
- Kevin Griffin
- Liberation Park
- The Mindful Addict
- Mindfulness-Based Relapse Prevention (University of Washington)
- 9 Essays: Buddhism & the Twelve-Step Model of Recovery (PDF) San Francisco Zen Center
- Paul Garrigan (Thailand)
- Thamkrabok Monastery (Thailand)
- Thamkrabok Information Network
- The Twelve-Step Buddhist
Neuroscience and Buddhism
- The Center for Contemplative Mind in Society
- Center for Investigating Healthy Minds (Richard Davidson at University of Wisconsin-Madison)
- Contemplative Mind in Life
- The Mind and Life Institute
- Mindsight Institute (Dr. Dan Siegel)
- Nalandabodhi: Gateway to a Buddhist Science of Mind
- Santa Barbara Institute for Consciousness Studies (B. Alan Wallace)
- Wisebrain.org (Rick Hanson and Rick Mendius)
Mindfulness in Education and Healthcare
- Association for Contemplative Mind in Higher Education
- Association for Mindfulness in Education
- Center for Mindfulness in Medicine, Health Care, and Society at UMass Medical School (see also: Jon Kabat-Zinn)
- Garrison Institute: Initiative on Contemplation and Education
- Greater Good: The Science of a Meaningful Life (UC Berkeley)
- Institute for Meditation and Psychotherapy
- Mindful Schools
- Susan Kaiser-Greenland
- UCLA Mindful Awareness Research Center
- UCSD Center for Mindfulness
Language Reference
- A Glossary of Pali and Buddhist Terms, edited by John T. Bullitt (Access to Insight)
- Digital Dictionaries of South Asia (includes Pali and Sanskrit)
- Manual of Buddhist Terms, Nyanatiloka
- Pali Text Society
- The Rangjung Yeshe Glossary of Vajrayana Buddhist Terminology
General Reference
- An Introduction to Buddhism (pages written for a university course on Buddhist psychology)
- Blogisattva Directory (English-language blog awards and reference site)
- BuddhaNet (multi-lingual site downloadable books, a worldwide directory for places to practice, and many other resources)
- Buddhism: About.com by Barbara O’Brien
- Dhamma Wiki: A Buddhist encyclopedia and reference on the Dhamma, Dharma
- Dharmaweb (wiki-type reference)
- DharmaNet
- Mugen Project (an academic and historical reference, bibliographic database – mostly Japanese)
- The Pali Tipitaka
- Patheos Buddhist Portal
- Rigpa Wiki
- Urban Dharma
- Wikipitaka
Buddhist Publications
- Barre Center for Buddhist Studies Publications (Insight Journal, Dhamma Dana Pubs)
- Bodhi Magazine
- Buddhadharma: The Practitioner’s Quarterly
- Buddhism Now (non-sectarian online magazine)
- Buddhist Channel (Buddhist news, headlines)
- Ch’an Magazine
- Dharma/Arte (Portuguese/English)
- Dharmalife (archive only)
- Forest Sangha Newsletter (Amaravati Monastery)
- Inquiring Mind
- Journal of Buddhist Ethics
- Journal East: A Buddhist view of current affairs
- Journal of Global Buddhism
- Mandala: The Official Publication of the Foundation for the Preservation of the Mahayana Tradition
- Mindful.org
- Mountain Record (Mountains and Rivers Order of Zen Buddhism)
- Pacific World Journal
- Parabola Magazine
- Prapañca Journal
- Present: The Voices and Activities of Theravada Women
- Shambhala Sun
- Tricycle: The Buddhist Review
- Turning the Wheel
Book Publishers
Educational Institutions
- Buddhism and Society (University of British Columbia)
- Institute for Buddhist Studies
- Naropa University
- Oxford Center for Buddhist Studies
- Center for Buddhist Studies, Rangjung Yeshe Institute (Nepal)
- University of the West
Forums/Online Communities
- Appamada (Ning)
- Buddhism – Reddit
- BuddhismIS
- Buddhism Without Boundaries
- Dhamma Wheel
- Dharma Overground
- Go Mindful
- Insight Meditation Center (Ning)
- Krishnamurti Information Network
- Krishnamurti Network (Ning)
- New Buddhist
- Prison Dharma Network (Ning)
- Tricycle Community (Ning)
- TTEM “Transformational tools, energy, mind”
- Unfettered Mind (Ning)
- The United Buddhists (Ning)
- Urban Refuge A virtual sangha for Buddhist practitioners of color, allies and others interested in promoting racial and cultural diversity in Western Buddhism
- Vipassana Forum
- What Meditation Really Is
- Zen Forum International
on the precipice 