Crossing Cultures
Contains personal stories of cultural experiences, essays, poems, artwork and photos.
http://www.digitrends.com/crossingcultures/

Ethnic group - Wikipedia
A general overview of what the term Ethnicity means.
http://en.wikipedia.org/wiki/Ethnic_group

Ethnologue: Languages of the World
The Ethnologue is a catalogue of more than 6,700 languages spoken in 228 countries. The Ethnologue Name Index lists over 39,000 language, dialect, and alternate names. The Ethnologue Language Family Index organizes languages according to language families.
http://www.ethnologue.com/

World Cultures
Database of statistics and indexed links about more than 8000 cultural communities worldwide.
http://www.freewebs.com/worldcultures/index.htm