Country Studies, from the Library of Congress, accesses studies of 100 countries. Political, economic, social systems and institutions are described.
Infonation allows you to view and compare the most up-to-date information on Members States of the United Nations.
The World Factbook 2008 provides country information gathered by the US Central Intelligence Agency from many government and private sources.
Yahoo - Countries accesses government, embassy, and other kinds of information about 147 different countries.