First World War is a website that provides a thorough history of World War I. This site provides a nice collection of useful resources including a detailed timeline, an encyclopedia, and articles on details that are widely known (Zimmerman Telegram) as well as more obscure people and events. You can also find a large selection of propaganda posters, maps, and vintage videos, audio and photographs from the war.
Wake Up America
Learn NC World War I Propaganda Posters is produced by the University of North Carolina at Chapel Hill and it provides 23 high quality images and informational captions that provide a unique glimpse into WWI.
Authentic History is a great history site that tells the story of World War I in four different categories. The Great War Overview, the Home Front, Woodrow Wilson, and the Bolshevik Revolution. Each section contains a wealth of information including examples of propaganda.
All World Wars
All World Wars has a nice selection of propaganda that are displayed with large high quality images. There currently are 56 images of posters from many of the different Allied nations.
WSU Propaganda Collection
Washington State University has one of the largest collections of propaganda posters with over 500 digital images from 1914 to 1945. The posters and pamphlets come from nations on both sides of the conflict. Each image is accompanied by detailed explanations and can be downloaded or printed.
Documenting the American South
Documenting the American South is another great source from the University of North Carolina. This collection has over 100 propaganda images categorized by type which includes finance, military, and industry.
Calvin College has a massive collection of German propaganda from pre-1933 up to 1945. This collection includes pamphlets, speeches, essays, art, cartoons and posters. Plan on spending a great deal of time here because there is so much to see and read.
Check out this collection of historic World War II posters from the Cincinnati Digital Library. This collection of over 85 World War II propaganda posters are from both the U.S. and other nations. Since they are digital they can be downloaded and printed for use in the classroom. History teachers should race on over to this site ASAP.
Psywar is a website with a amazing collection of propaganda leaflets that were dropped by the participants of both WWI and WWII. The site is searchable by name, type of message, and even by nation. This is another website with an overwhelming amount of propaganda related materials.
World War II Posters
Northwestern University has a collection of over 350 digital images of various propaganda from WWII. The resources can be searched by topic or by scrolling down the page to see the various posters. Each selection is accompanied by information including the government agency responsible for the publication and the year.
Vintage Ad Browser
The Vintage Ad Browser is a website that features a huge collection of over 100,000 old posters and advertisements from as far back as the 1700's. The website has a large selection of propaganda posters from the 1800's up to the 2000's but note that most of the posters after the 1940's are from Communist China.
World War II Museum
The World War II Museum has a great section dedicated to the various types of propaganda. The real advantage to this site is their built in educational resources. From the home front to the soldiers overseas, this site has posters and lesson ideas to accompany the various topics.
This Flickr account (Heavyovmetal) has 128 great images of World War II propaganda. This page lacks the important information that accompany the images in the other websites listed but if you want a quick and simple way to see the various posters, then this is the place to go.
The Digital Comics Museum is a collection of comics from the "Golden Age of Comics" (1930's-1950's) that are now "public domain and have been put up on the net. Finally, the Digital Comic Museum has educational value because it provides a snapshot into American culture of the time. These comics were published during World War II as well as the earliest days of the Cold War so there is plenty of propaganda to be found for the social studies teachers out there.
Another website that specializes in propaganda comic books can be found at this page from Retronaut which has a nice selection of propaganda related comic books form the WWII era. This site only displays Comic Book propaganda so it give you much quicker access than the Digital Comic Museum which does require a certain amount of searching.
Below you will find two YouTube channels with various types of propaganda videos in their collections.
Human History Archive
This You Tube Channel has an nice collection of videos, many which are propaganda related.
This channel has a massive collection of vintage films, many of which are propaganda films.