My boss has a wordpress site and he wants me to give him the ability to add videos from a site called vzaar. I see the form, I see the main PHP file for editing posts. Unfortunately I can't track the form down to the backend file. How can I know which file I want to edit. The theme were using is called mercurial. All I need to do is add one select box and probably some backend logic.
My background: I'm really familiar with Ruby on Rails, but have little experience with PHP. Seems simple enough, i'm just not super stoked about having to re-engineer the WP theme.