First image used

Maurizio,
In the zip file you downloaded, there's an opengraph directory. Install and publish the Open Graph - Content plugin. By just doing that, JFBConnect will automatically set the first image in any article to the Open Graph image tag for that page. There's lots of configuration and customization you can also do if you want more control, but that's the easiest.

Once enabled, it can take Facebook 2-3 days to detect the change. However, you can use the Facebook URL debug tool on some pages of your site to check what Facebook 'sees' for the Open Graph tags. That also updates their cache immediately for that page, which is a nice benefit.

I hope that helps get you going, but if not, just let us know.

Thanks,
Alex