United Nations Statistics Division
http://unstats.un.org/unsd/default.htm
The Statistics Division of the United Nations collects, processes and disseminates international statistics, providing a global centre for data on international trade, national accounts, energy, industry, environment, transport, and social statistics. The site offers access to the Division’s databases, latest publications and reports, newsletters, and information on methods and classification.

The United Nations Education, Scientific and Cultural Organization (UNESCO)
http://www.unesco.org
Founded in 1945, UNESCO is a specialised United Nations agency dedicated to creating respect and dignity for diverse cultures and values, and disseminating and sharing knowledge in the fields of education, science, culture, and communications. See http://www.uis.unesco.org/[...] for the UNESCO Institute of Statistics, a comprehensive information portal presenting global statistics on education, science, technology, culture, and communication.

The Organisation for Economic Cooperation and Development
http://www.oecd.org
The Organisation for Economic Cooperation and Development (OECD) is a 30-member country organisation active in fostering democratic governance and the market economy. The OECD statistics page ((http://www.oecd.org/std/) contains access to key statistical information on trade, education, development, science, and innovation.

World Health Organization 
http://www.who.int/hac/en/
The World Health Organization (WHO) is a specialised United Nations agency established in 1948 to promote health in all peoples of the highest possible level. The WHO website contains news, events, fact sheets, contact information, multimedia, speeches, biographies, and publications. Information on disease outbreaks, emergencies, country profiles, health topics, statistics, and disease classification can also be accessed on this site, along with access to WHOLIS, the WHO online library database.