Can I see all website files?

Is there a way to find website pages that are not linked to on any other page? I want to be able to see all files associated with a website. For example if I visit www.familyguyfiles.com I want to find pages or files not linked to on any page. Maybe there's a hidden page or hidden files?
I've done this on my own .com's in the past to allow my friends to see pages that I created with out making them available to the general public.

thank
DH