Identify Pages

What's the easiest way to determine what each 'pagexx.html goes too?

well for modules  they are in the template folder of the module directory.  As for the rest of the site its a bit harder.  You will have to look at the source code and find where it is hard coded for say page1.html which would be in index.php....  

profile.php might be page5.html ... and so on.    line 55  $_page['name_index'] = 5;

I don't think there is a easy way for site wide but modules are pretty easy.