Nuclear War Survival Skills is a free online 270 page book. Ton's of information! As complete a reference as you'll need.

Map a Nuclear Blast, an interactive page from PBS where you can learn the effects of a nuclear blast on any address in the United States.

Shelter Designs, a collection of free designs for various shelters.

Doomsday Clock The current time of the Doomsday Clock, from the Bulletin of Atomic Scientists. Be sure to check out the Timeline, a history of the clock and its past time swings.

How Nuclear Radiation Works from howstuffworks.com. Easy to read, well illustrated and informative.

Three Mile Island, a book on the Washington Post website, This link goes to Chapter 6, where radioiodine fallout is discussed.

RadNet, a rather technical site. Radnet documents and reports on plume sources and dispersion of radiation.

You can buy Potassium Iodide pills at Nitro-Pak.com .