News feed picture for Facebook like button

We'd recommend going to the Open Graph -> Settings area in the admin section of JFBConnect. Then, in the 'defaults' box, you can add the following:
image=http://yoursite.com/link-to-image.jpg

That will set that image as the 'backup' image on all pages of your site. That's great for a logo or something that would work on all pages.

Then, on any page you want a different picture, use the {SCOpenGraph image=...} tag or use the Open Graph plugins for that extension to have the image automatically set.

Hope that helps,
Alex