I'm trying to get links to my albums to show up in Facebook with thumbnails.

Reading this forum points to the issue being missing OG tags and there is a plugin to fix this.
I've installed the "Metadata Open Graph" plugin but don't really understand how to use it.
I've filled in a few fields but when I got to "Facebook App_ID" I ended up going all over Facebook developer's pages trying to get one, and failed because it wants all sorts of stuff I don't have.

Am I doing this all wrong? What is the easiest way to get Facebook to show thumbnails whenever I post a link?