Infographics present different kinds of information in a visual or graphic form.  They are extremely useful in the classroom because they can summarize information and take dry statistics and make them interesting and attractive.

http://www.easel.ly/ - in Beta as of May, 2012 but has some great functionality

An excellent presentation by Kathy Schrock: https://sites.google.com/a/kathyschrock.net/infographics/

     * Note the link to a resources page!

David McCandless in the opening to his TED talk, The Beauty of Data Visualization

10 Awesome Free Tools to Make Infographics: http://www.makeuseof.com/tag/awesome-free-tools-infographics/

New York Times: Teaching with Infographics - http://learning.blogs.nytimes.com/2010/08/26/teaching-with-infographics-language-arts-fine-arts-and-entertainment/

and Places to Start: http://learning.blogs.nytimes.com/2010/08/23/teaching-with-infographics-places-to-start/

 about how the Graphics department creates them.

10 TIPS For Designing Infographics by Randy Krum - http://digitalnewsgathering.wordpress.com/2010/04/24/10-tips-for-designing-infographics/

Examples of Infographics: http://www.coolinfographics.com/

and http://sixrevisions.com/graphics-design/40-useful-and-creative-infographics/  

http://www.quora.com/Infographics/What-are-some-of-the-most-innovative-infographics-on-the-internet