Wolfram Research
Wolfram Math World: Ellipsoid
This site from Math World begins with a picture of an ellipsoid and then gives cartesian and parametric equations for the surface. The site gives much more information for the ellipsoid, including special ellipsoids, a surface area...
National Council of Teachers of Mathematics
The Math Forum: Ask Dr. Math: Calculating Surface Area of an Ellipsoid
Dr. Math, in a reply to a student question, discusses how to calculate the surface area of an ellipsoid.