Good Information from the EPA

The EPA:
Molds can be found almost anywhere; they can grow on virtually any organic substance, as long as moisture and oxygen are present. There are molds that can grow on wood, paper, carpet, foods, and insulation. When excessive moisture accumulates in buildings or on building materials, mold growth will often occur, particularly if the moisture problem remains undiscovered or unaddressed. It is impossible to eliminate all mold and mold spores in the indoor environment. However, mold growth can be controlled indoors by controlling moisture indoors.

http://www.epa.gov/mold/moldguide.html

EPA links:
"A Brief Guide to Mold, Moisture, and Your Home"
For basic information and resources on mold, go to our Mold Resources page