This site has an emphasis on the researching of undocumented indigenous languages around the world. It provides significant resources to assist fieldworkers and researchers. (
http://www.sil.org/linguistics
)
Affiliated with SIL International (formerly known as the Summer Institute of Linguistics, Dallas, Texas), this site enables easy access to information on nearly seven thousand languages spoken in 231 countries. (
http://www.ethnologue.com/web.asp
)
This site provides an overview of language and anthropological linguistics. It addresses all aspects of human communication. (
http://anthro.palomar.edu/language/default.htm
)