Home Buyers And Sellers Guide To Radon
This site has almost everything I can think of regarding radon, testing for radon and remediation. Very good place to search for answers from a home buyers, home owners or home sellers point of view.

Radon Resistant New Construction Features
Good site for the interested home building professional to start with or for someone building a new home.

Virginia Dept. of Radiological Health
This is the Virginia Department of Radiological Health's radon homepage.

University of Iowa Radon/Lung Cancer Study
The results of a UI study finding residential radon exposure poses a significant lung cancer risk.

University of Minnesota Environmental & Occupational Health Radon Health Study
How Radon causes lung tissue damage.

National Radon Proficiency Program
A must visit prior to selecting a Radon Testing or Mitigation Professional. They have listings nationally and by state.

National Radon Safety Board
Some Radon Professionals are also listed here.

American Assoc of Radon Scientists and Technologists
Many Radon Professionals are also a member of this organization. It's more of a trade organization.

Employee Relocation Council
ERC is a good site for people interested in information regarding relocating employees or business that may assist them in this process.

Cansar.org
Lung Cancer Victims & Their Stories

State Radon Requirements
Individual state radon requirements

Journal of Pharmacy and Pharmacology: Mechanism of radiation-induced bystander effects: a unifying model
See my blog for the shorter version

What are the properties of radon?