There is a very detailed and up to date guide here. The below is more of a quick guide.
- To edit navigation menu at top of site: Select Appearance » Menus from left sidebar.
- You can add pages by clicking on Pages and selecting the pages that you want to add. They will then automatically appear in the menu on the right. You can rearrange them via drag and drop.
- You may wish the menu title to be different to the page title (page titles are often too long). To change, click on each and change the ‘Navigation Title’
- In particular, you should change the title of the home page to ‘Home’ and put it first.
You can also edit menus via the Customize page.
- It is best not to have more than 5 links
- The links serve as a ‘quick access’ guide to the visitor, so think about what they want when they visit your site.