This inspection includes the placement of testing devices to measure the ongoing level of radon in the habitable areas of the home. These measurements evaluate the level of radon to determine if any form of improvement is required.

There’s an EPA document that provides the basic information everyone should know about Radon. And can be referenced at: A Citizen’s Guide to Radon

Other guides that are also available for download from the EPA website are:

Home Buyer’s and Seller’s Guide to Radon
Radon in Schools
Radon: A Physician’s Guide

Other Radon-specific publications are located at:
Indoor Air Quality-specific publications

If you plan to make repairs yourself, be sure to contact your state radon office or visit the publications site for a current copy of EPA’s technical guidance on radon mitigation:
Regulations:Where You Live

Another great site for additional information is: How Stuff Works-Radon