For mod_jfbcfan, you need to use a Fan Page URL, which is a page on Facebook to represent your company. It will look like the following:
www.facebook.com/pages/SourceCoast/141717952527296
That's our SourceCoast Fan page, and you can see what that module would look like with that URL at
www.sourcecoast.com/jfbconnect/features/...la-facebook-like-box
The friends module works by letting the user know:
* Who else has liked the current page of their friends. You configure it this way by setting a URL in the parameters to specify the page to show if the user's friends have Like'd that URL.
* Who else has logged into your site using Facebook. You configure the friend module this way by leaving the URL blank. This then tells Facebook to look to friends who have joined (logged into) the application.
Fan pages and your application are separate though. So the Friend module and Fanbox are unrelated. A user can Like your Fan page -or- join/like your site (using Login with Facebook), but they don't have to do both.
I hope that makes sense and helps explain how the 2 modules work.