Explore the U.S.
Fact Monster - http://www.factmonster.com/states.html
Kids U.S.A. - http://kids.usa.gov/learn-about-the-states/index.shtml
U.S. Consolate for Kids - http://www.usconsulate.org.hk/pas/kids/50states.htm
Research on the World
The World Fact Book - https://www.cia.gov/library/publications/the-world-factbook/index.html
Fact Monster - http://www.factmonster.com/countries.html