The Display sub-menu items within Folder? option that you see on the News page is equivalent to adding the Child List includelet onto a page and then publishing it.

The Child List includelet will add a list of links to all pages below the current page.

You can also use the Filtered Item List includelet to do this - it has loads of options which can be a bit overwhelming at first, but has the advantage that you can choose to display the links in different ways, such as a grid with images, rather than just a plain list.

Another option is to tick the Include in navigation menu? option on your pages so that they show in the main navigation.

Thanks

Joe