Play and Learn 
A good collection of articles on Islamic history, Fiqh and scholars. Also has a children's section.
http://www.playandlearn.org/Shi'a home page
Site has Articles about Islamic fundamentals, the Imams and important Muslims. Also has a list of Islamic organizations and websites.
http://www.shia.org/
Rafed Network for Cultural Development
Resources on Islam, the Shia and the Ahlul Bayt.
http://www.rafed.net/
Scientific and Cultural Institute of Dar al Hadith
Produces publications in the field of hadith in Arabic and Farsi, including books, journals, and software. Includes articles on Shia use of Hadith traditions. [English, Arabic and Farsi]
http://www.hadith.net/
Tafseer Al Mizan
An introduction to, and some chapters of, an exegesis of the Qur'an by Al-Allamah al-Sayyid Muhammad Husayn at-Tabataba'i. Also includes articles, and FAQ.
http://www.almizan.org/
Shia Match
Aims to assist Shia Muslims in finding a suitable match for Marriage.
http://www.shiamatch.com
Islamic Books Online
Publishes and distributes a range of books to make the teachings of Prophet Muhammad and the Ahlul Bayt available. Online shopping.
http://www.islamicbooks.org/
Converts to Islam
Offers information on Islam, convert stories, and advice sections for new Muslims.
http://www.convertstoislam.com/
Al-Islam
Site which serves as a resource for anyone wanting to learn about Islam, whether you are a non Muslim or a Muslim. Includes a large collection of online books and multimedia resources.
http://www.al-islam.org
Roshd
Articles on prophethood, resurrection, Imamat, justice and Quran. Multimedia section included.
http://www.roshd.org/
Islam from the inside out
Islam and Islamic issues from a philosophical, esoteric viewpoint - looking from the inside out.
http://www.islamfrominside.com/IslamfrominsideRSS.rss
The Light of Islam
Resources on Islam including the Holy Quran, the prophet of Islam,the Holy Imams, books and articles.
http://islam.web1000.com
Shi'a Islam
A schematic overview of the Shia tradition, with articles on the main groups.
http://philtar.ucsm.ac.uk/encyclopedia/islam/shia/
Islam for Dummies
Substantial collection of resources on Islam from a Shia perspective, with a strong emphasis on mutual respect between Sunni and Shia.
http://www.ezsoftech.com/islam/
Al Muntazar
E-zine which aims to propagate Islam; includes an archive of previous editions.
http://www.almuntazar.com/
Revert Muslims Association
An on-line community and resource portal for those new to Islam. Includes a forum, resources about faith and practice, and revert stories.
http://www.revertmuslims.com/
