Acid Rain
   Explains what causes acid rain, and what it does to forests.
   http://www.ec.gc.ca/acidrain/

Acid Rain Formation
   Has a picture that shows how acid rain forms, and why it's bad.
   http://www.rpi.edu/dept/chem-eng/Biotech-Environ/Environmental/acidrain/kids.html

Atmosphere, Climate and Environment: Acid Rain
   Explains what acid rain is, how we measure it, and what it's doing to buildings and our health.
   http://www.ace.mmu.ac.uk/kids/acidrain.html

Burning Rain
   An experiment that explains the difference between an acid and a base, and describes the cause and effects of acid rain.
   http://www.nps.gov/lacl/kids/acidrain.htm

EPA: Acid Rain Kids Site
   Tells the tale of Lucy Lake and has games.
   http://www.epa.gov/acidrain/education/site_kids/

Wikipedia: Acid Rain
   The history of acid rain, why it occurs, and how it can be prevented.
   http://en.wikipedia.org/wiki/Acid_rain