Building a fallout shelter is one of the basics of radiation protection. There is more information on emergency shelters in the free Nuclear War Survival Skills book.

The following zip files contain plans for shelters:

Backyard Blast Shelter

Above Ground Fallout Shelter

Below Ground Fallout Shelter

The above shelter plans were digitized from FEMA plans by Robin Hanus. You can find her site here:
www.bwolf.com

Check out Nitro-Pak.com for emergency supplies.