Here is a step by step process on how to insert a link into an image in your signature...
As
MadlyAlive pointed out, it's good to know how to insert a link into a 'userbar' or any other image in your signature. If you click on the CBM userbar in my signature, it sends you to the Coz Boogie Militia thread. That userbar has a link in it. The following post will tell you how to do this.
1) After you have your signature saved, it should look like this...
2) Find a link that you want to insert. You can copy the URL out of the browser to do this by right clicking and copying the URL. I have selected the PPC Geeks Article on Wikipedia...
3) Now click on the image (you want a link to be on).. It will have the an outline around it, like the one pictured below.
4) Now hit the link button
<- - - (this) on the advanced edit toolbar.
5) Once the dialog box pops up, right click and paste the URL into the box. Now click 'Ok'
6) Now you just need to click 'Save Signature' to save what you have done or click 'Preview Signature' to preview how it looks... After saving it, you can click on that image and it will send you to the link you inserted...
7) Congrats.. You have now inserted a link into the image.