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.
Encyclopedia Mythica
Encyclopedia Mythica: Greek People (Mythological)
Featuring the heroes, heroines, and mythical creatures from Greek legend, this site offers information on hundreds of characters, as well as etymology, pronunciation, pictures, and more.
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.
Eserver
E Server: Drama Collection: The Plays of Sophocles
Full text of Sophocles' plays is available here, with easy printing and emailing functions.
Other
Ancient Greek Theatre: Sophocles
A personal site on Greek theatre with a brief biography of Sophocles, along with a short list of his works and summaries of each.