Hi Drood I think you have 2 options
1) use the page widget underneath the navigation and what ever pages you have created will show up.
2) use a program like notepad++ (not notepad) to open nav_menu.php and include the pages you want in there…
Ive normally just copied the second line and pasted it under depending on how many pages I want to show up…then upload them back onto your server.
2a) you could edit this file within wordpress but I never have!!