(standard disclaimer: these links were live in July 2012; apologies in advance if they're no longer active)

Primary Sources

Vintage Food Ads of the 1950s - VintageAdBrowser.com
Vintage Advertising of the 1950s - Found in Mom's Basement blog
Steve Czekalinski & Family with a Year of Food (1951) - "The Cost of Living in the Cold War," Wessels Living History Farm, York, Nebraska
Civil Defense Brochures of the JFK Era (not downloadable, but readable in their entirety online) - PopCult Magazine; some can be downloaded from Internet Archive
NSC-68 (the 1950 report, declassified in 1975) - full text here
1954 Senate subcommittee hearings on role of comic books in juvenile delinquency
The FBI File on Senator McCarthy

Relevant Presidential Libraries

Truman Library- includes "The Spy's Dilemma" - simulation focused on which early Cold War document would be most useful to a spy (11th grade)
Eisenhower Library
Nixon Library

Video Clips

"Duck and Cover" on Internet Archive (9:14)
"Two Ford Freedom" ad mid-50s on Youtube (1:39)
Dinah Shore, "See the USA in Your Chevrolet" 1952 ad on Youtube (1:33)
Coca-Cola Ad/ Drugstore fountain 1953 ad on Youtube (1:43)
Some 1950s Sci-Fi Horror movies evoke (indirectly) the atomic threat. E.g. "THEM!" (1954)

Edward R. Murrow's CBS news investigation program, "See it Now" for March 9, 1954 - his closing editorial re: Joseph McCarthy