Steve,

I'm assuming you are talking about an "images" folder within a custom module that would be stored in the "DesktopModules" folder, right?  Assuming I'm correct you could put the src as src="/DesktopModules/MyModule/images/myImage.png"; if you are talking about the root images folder you could use src="/images/myImage.png"

One thing to note here is that the above work when the application is ROOT on the domain.  In other words if your DNN app is hosted directly in www.mydomain.com then the above would work.  However, if it were a virtual directory under the domain such as www.mydomain.com/myapp you would have to include /myapp before the leading slash in my example above (so src="/myapp/images/myImage.png").

Make sense?