let's say you want to add a new widget area to the footer. you go to 'Style & edit FOOTER' and put the code into the text area named "Footer: Content".
To make the widget area, you can use the shortest and most basic code which would be:
<?php bfa_widget_area('name=My_footer_widge_ area'); ?>
save the option and now go and view your page. The reason you do this is to actually execute this code which will create the new widget ares.
Next go to dashboard->appearances->widgets and you should see your new widget area. Now simply drag a widget into it and your all done. Go back and look at your site and you should see the widget in your footer.
Remember this code only creates the widget area, it doesn't create widgets, you can add one or more widgets to the widget area just like any other widget area (ie the sidebars)
Now go experiment.