Biology 4 kids
Biology4 Kids: The Top Four Kingdoms
Read about the four most familiar kingdoms: fungi, plant, animal, and protist.
Other
Panhandle Area Educational Consortium: The Six Kingdoms of Life [Pdf]
Scientists look at the evolutionary history of organisms to divide them into kingdoms. For awhile, there has been 5 kingdoms, but many scientist are now using 6 kingdoms.
Other
The Domains and Kingdoms of Life
This site is a description of the history behind the 5 Kingdom system suggested by Robert Whittaker. An extensive list of resources is included.
National Institute of Educational Technologies and Teacher Training (Spain)
Ministerio De Educacion: La Clasificacion De Los Organismo
This unit will describe the five kingdoms and their main characteristics. It includes 20 interactive activities.
National Institute of Educational Technologies and Teacher Training (Spain)
Ministerio De Educacion: Clasificacion De Los Seres Vivos
All known form of life gathers in large groups, which are called kingdoms. This site provides a thorough overview of the five kingdoms with many illustrations. The lessons contain 15 interactive activities.