“A Citizen's Guide to Radon: The Guide to Protecting Yourself and Your Family From Radon (4th ed.)”
This online version of an EPA printed guide is a GREAT resource.  It is easy to understand, illustrated, comprehensive, and even debunks many of the common myths about Radon.

US EPA's Radon Home Page
Recent News, Radon Publications, Hotlines, A - Z, and many other useful links and resources.

AARST Radon Info Page
The American Association of Radon Scientists and Technologists links page with over 40 links to EPA, Health Effects, Research and Study resources.

Radon: Buying and Selling a Home in Fort Collins
Answers to all the important questions about radon and real estate transactions from the Air Quality Program of the Fort Collins Natural Resources Department.