Acid Rain: Explains what causes acid rain, and what it does to forests.
Acid Rain Formation: Has a picture that shows how acid rain forms, and why it's bad.
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.
Burning Rain: An experiment that explains the difference between an acid and a base, and describes the cause and effects of acid rain.
EPA: Acid Rain Kids Site: Tells the tale of Lucy Lake and has games.
What is Acid Rain?: Looks at the effects of acid rain, and how factories and cars can cause it.
Wikipedia: Acid Rain: The history of acid rain, why it occurs, and how it can be prevented.