With standard HTML, it's easy to make a picture into a link. If you already know how to make a link, like this:
<a href="your_url_goes_here">Click here!</a>
And you already know how to show an image, like this:
<img src="your_picture.jpg" />
Then you can combine those tags to make an image into a link:
<a href="your_url_goes_here"><img src="your_picture.jpg" /></a>
See that? You're just replacing the text ("Click here!") with the code to generate an image.
Of course, if you're using Mainspring, you don't need to use HTML! Contact us for a demo!