University of Virginia
Uva: The Real World Air Resistance
A contrast of Galileo and Aristotle's view of inertia and motion. Describes air resistance force and how its reality seems to initially support Aristotle's view.
NASA
Nasa: Beginner's Guide to Aerodynamics
This site from NASA uses a colorful graphic to illustrate why objects reach terminal velocity. Provides equation for the terminal velocity of an object. Graphic is accompanied by a simple explanation.