Britannica.com: Chad History
An excellent history from Britannica.com.

Country Study: Chad
This comprehensive book-length information from the Library of Congress includes an entire chapter (chapter one) of history of the country.

Flags of the World: Chad
Information, images, and available history of the current and past flags of the country.

Geography and Maps of Chad
A plethora of geographical information and online maps from the About Geography site.

Infoplease.com: Chad Overview
A fantastic short historical overview, contemporary data, and a map from Infoplease.com

Lonely Planet: Chad History
An in-depth history of the country from Lonely Planet, the travel guidebook company.