Use the Section content type to create nested pages for your site and do it well of course. Section should be used for the key informational portions of your site such as About or Services. These sections are relatively stable and often have sub-sections. You can easily add "child" pages to create sub-sections and re-order as necessary using book functionality. Learn about using sections via the documentation.
You can edit this page to describe your organization and then edit the Mission child page to add in your mission, or delete it and add the sections you need.
To change the menu listing for About, edit via the Menu settings tab on this page or via the Menu administration page (admin/structure/menu).
To add more child pages (sub-sections), click the Add Child Page link at the bottom of a section.
To change the order of your child pages, select the Books tab under Content (admin/content/book).
This is a child page of the About section. You can edit this page to add in your mission, or give it a new title and use it to add another subsection, such as Board or Staff or delete it entirely.