California State University
Cal State, San Bernadino: Hyperbolas
An excellent site describing the equations for hyperbolas, including graphs of hyperbolic functions and multiple exercises for practice.
University of Georgia
University of Georgia: Hyperbolas
A four-lesson tutorial on hyperbolas, the standard form for hyperbolic functions, and how to graph them. Includes a lesson quiz.
Discovery Education
Discovery Education: Web Math: Graphing Hyperbolas
WebMath offers a java applet that allows you to input information about hyperbolas in one of eight forms and gives you the graph of the hyperbola.