PBS
Pbs: The Sophists
Describes the subjects taught by the Sophists and discusses the diversity among sophist doctrine.
Other
The Sophists
A summary on this group of "teachers" and their beliefs. The author identify some of the major "Sophists" and their ideas.
Stanford University
Stanford Encyclopedia of Philosophy: Aristotle's Logic
Thorough explanation of Aristotle's several original contributions to logic from the Stanford Encyclopedia of Philosophy. Includes a substantial bibliography as well as sections on syllogism, assertion, demonstration, the "Organon,"...
Internet Encyclopedia of Philosophy
Internet Encyclopedia of Philosophy: The Sophists
This site from the Internet Encyclopedia of Philosophy provides a good summary of the Sophists, their history and motives. Lists major figures.