The Menu section of the Control Panel (under Settings) allows you to control the menu links on your site.

You can change the order of how the menus appear by dragging the icon next to the menu items.
You can rename the menu links by clicking on the menu link titles and typing the new name
You can also choose whether each menu item should be in the primary menu, the secondary menu, or off.

After you make changes on this page, make sure to click the "Save Changes" button at the bottom of the page.

You can completely customize the menus for your site. There are two areas for menus – a "primary menu" and a "secondary menu". Often the secondary menu might be in one of the left or right columns and would be links to perhaps second-level material. Primary links are often first-level material and might typically be found in the navigation bar area. However you can experiment with links in either menus and place them wherever you like.

One caveat is that themes may presume a maximum number of menu items in the navigation bar area. If you exceed that number the site may look funny. That said, you're welcome to present your content in any way you prefer.

If you create custom menu links, they will also be displayed here. Some columns may be greyed out which means that the feature responsible for this menu item is not enabled. Features can be enabled under the "Features" tab in the Control Panel.