To add the Register With Facebook button, you'll want to create a template override for the default Joomla registration page. To learn more about template overrides, see the bottom article on the page below:
www.sourcecoast.com/extensions/troublesh...ng-joomla-extensions
The specific override you'll want is to copy the file below:
/components/com_user/views/register/tmpl/default.php
to
/templates/<YOUR_TEMPLATE>/html/com_user/register/default.php
Once there, edit the new file and add {JFBCLogin} wherever you want the button to show. JFBConnect will replace that with the "Login with Facebook" button.
Hope that helps, but if you have any other questions, just let us know!