Dynamic Content Gallery

I’m confused about the Dynamic Content Gallery.

I believe I have it configured correctly. However I’m not sure as to what code I should post and where I should post it.

Am I correct in assuming that the code

add_theme_support(‘post-thumbnails’);

is placed in the themes function.php file and that when you get to individual posts within your WP that you enter your full URL into the DCG Metabox and you also create a custom field called dfcg-image and also post the full URL into there. In addition you also create another custom field called dfcg-desc

I’m just a bit confused on what goes where ??