You need to venture a little into HTML. First you upload the image to a spot on the web, and then you point to it like this:
<img src="http://www.50interviews.com/amazon.jpg">
Here’s how the entire widget looks like to have a hyperlink to your graphic:
<a href="http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F%2Fwww.amazon.com%2F&tag=50interv-20&linkCode=ur2&camp=1789&creative=9325"> <img src="http://www.50interviews.com/amazon.jpg">
This is how I created the widget with the amazon graphic you see on the far right.