Interaction International: http://www.tckinteract.net/
Interaction International is the world’s foremost organization advocating on behalf of third culture kids of all ages, nations and backgrounds. For nearly three decades, Interaction International has been spanning the globe; working tirelessly at making the lives of every TCK and their families count.
TCK World: http://www.tckworld.com/
TCK World contains a wealth of information about all kinds of TCK issues, including MKs as well as many others who have gown up between cultures. It includes many resources, events and links to information.
Families in Global Transition: http://www.figt.org
Families in Global Transition believes in the capacity of the expatriate and repatriate family to transition successfully and to use the international experience for all of its human and global potential. Their goal is to support the family and provide resources for families who live, move, and work throughout the world.
An American Abroad: http://www.an-american-abroad.com/
This is an online resource for Americans Abroad and/or those seeking to go abroad. With news, columns, community forum, reviews, shopping, tourist info, tool & guides, publications, country reports, links, etc., their goal is to promote travel abroad, educate Americans within the US about the outside world, form a community for Americans residing overseas, promote respectable products & services pertaining to your needs and wants, and make life simpler by putting a lot much more under your fingertips to save you time.
ExpatExchange.com is an online community for English-speaking expatriates. Their community supports expats through all phases of the expatriation and repatriation process. It is their goal to build the most useful online pool of resources for individuals living outside of their country.
MK Connection: http://www.mknet.org/
MK Connection is a central place for finding things of interest to MKs and other TCKs. It contains links to schools around the world, writings by TCKs, web pages, and mailing lists for connecting with other TCKs.
ExpatExpert links: http://www.expatexpert.com
ExpatExpert has dozens and dozens of links valuable to cross-cultural workers.
Interculteral Press: https://openlibrary.org/publishers/Intercultural_Press
Intercultural Press has a very large selection of books relevant to living and working in cross-cultural situations. These books are not free, but most published by Intercultural Press are valuable additions to your library of information.