AKA Informational Graphics
I would describe them as picture graphs. They are more than just a bar or pie chart. Infographics are more interesting and creative. They use a picture (graphic) to describe the information being displayed in the graphic.
MSN provides a website called Good Infographics. I like this site because it shows the creative aspects of infographics. I am not a big fan of reading the news. This site takes the news and makes it into infographics. For example this is the infographic the site uses to talk about the rotarvirus.
I think that this could be very helpful for PR professionals to use with clients. PR professionals can use infographics to plot out a more interesting timeline. They can also use it to spice of graphs used from research. The infographics will definitely give PR professionals a creative spin showing their talents off to the client.
I feel like an infographic takes a lot of talent to create. So my advice with how to make one is have some sort of a graphic design background. If you want a tutorial, here is a video of a guy creating one himself.