Massachusetts Institute of Technology
Mit: Internet Classics Archive: Works by Sophocles
The seven plays by Sophocles written out and followed by commentary. No biographical information is given.
Other
Sophocles: The Man and His Plays
In addition to the usual biographical material and links to English translations of his plays, this includes a long discussion of "Oedipus the King," Sophocles' most famous work.
TheatreHistory.com
Theatre history.com: Sophocles and His Tragedies
This site provides a complete biography of Sophocles reprinted from a drama history book. Includes his innovations in ancient theater and his achievements as an artist.
Eserver
E Server: Drama Collection: The Plays of Sophocles
Full text of Sophocles' plays is available here, with easy printing and emailing functions.