I’m assuming you have created a page called "projects page" or something like that, the link to the page should show up in your listed pages in the sidebar, or whereever you put them. If you create another page called "sub project1" or whatever, before you publish the page go to the right, and there is a drop down menu where you can define that page’s parent. in this case you would probably want the projects page as the parent. from that point on the sub project link should be shown as a sub page of project page. I think befault all child pages or subpages are displayed in the nav, or listed pages.
I have mine set up so the sub pages are only displayed on their parent pages, and not the main page.
that was kind of wordy, but does that help at all?
