Add Image w link below every post or page

http://www.bridaltribe.com

I would like to add a clickable image to the bottom of every post and/or page. I really am not looking to just have it in the footer area. I would prefer a plugin if possible, but coding is ok also. I just don’t want to have to go back to all of the old posts and pages and manually adjust them to show it.

Any suggestions?

Thanks