US Geological Survey
U.s. Geological Survey: Water Cycle
An in-depth explanation of the Earth's water cycle, including a hyperlinked diagram that provides direct access to information about each phase in the cycle.
NASA
Nasa: Introduction to Clouds [Pdf]
NASA is interested in clouds because they are an integral part of the water cycle, and because they are a controlling factor in the energy budget of the Earth. This chart provides a basic introduction to the identification of clouds. The...
abcteach
Abcteach: Earth
[Free Registration/Login Required] Ready made worksheets for any earth science unit on water cycles, the layers of the earth, or volcanoes.