I really like a div box that is styled a particular way on another webpage.
I'd like to incorporate the box into my website.
Is there a simple way that I could get the div box on my site? (I feel like I'm going to have understand the entire CSS file before I can make something similar, that is why I am asking).
Usually it is not that hard.
Try out firefox and some extensions:
They can help you with highlighting the needed css code. Just play around a bit with it.
You don't have to understand the whole site CSS by yourself, let the computer do its job.
Get some inspection tool like Firebug (for Firefox) or Dragonfly (for Opera) and see which rules are applied to the box you want and its inner elements. This way you may easily rip only the required rules (just copy and paste non-striked-out ones from the right part of the CSS pane in case of Firebug).