Have a main page (index.php), and then, all other pages can
be one dynamic PHP script, example: page.php?p=2 or page.php?p=13
Those variables will determine which "includes" will be used for
the content of the pages. See example below ... mouse-over the
links in the menu, notice the URL. The actual menu can also be a
PHP script, so you only need to edit one file if you add more navigation
items (and the navigation script is also a PHP include).