Info Please http://www.infoplease.com/ This site is for kids to get information.
Dictionary Online http://dictionary.reference.com/ This site is for students to get to an online dictionary.
Thesaurus Online http://www.thesaurus.com/ This is for students to get to an online thesaurus.
Fact Monster http://www.factmonster.com/ This site has many tabs for various subjects and also tabs for a dictionary, encyclopedia, thesaurus, almanac, atlas, and timelines.
Library of Congress https://www.loc.gov/families/ The Library of Congress is an ideal site for research.