Your site's menu is easy to manage and maintain.
You can add more content, order content, create drop down lists, edit names, links to external sites and much more.
Classic mode Left hand menu: Appearance >> Menus
You can simply drag and drop you list to create the order that you want.
You can use the custom links to create links to specific areas in your site or even on other sites. Just give it a name and a link and click add.
When creating drop down menu's these are super useful. They allow you to create a parent menu item which can contain drop down children, but when clicked won't go to a specific page on the site, but just show the child items.
You can then drag your chid item to indent under your parent item.
Obviously tho, your theme must support drop down menus and the option should be enabled for it to work.