After selecting Menu>Menu Manager>Top menu>New>

Click Articles.

Under Articles, you have several choices:

Article Layout - this means a link to an article.
Article Submission Layout - this means you want to link to a page where your site visitors can submit an article to your site.

Category Blog Layout - This creates a link to a Category, where it will display the articles on the category page, or where it will display article summaries on the Category page. You have a LOT of configuration options for this choice, to make it look just as you want, but it takes some time to make all the bits work together to get your layout right.

Category List Layout - This creates a link to a Category, where it displays a list of article titles. Not many configuration options, but fast to link because you don't have a lot of settings to tweak.

Section Blog Layout - Similar to Category Blog Layout, but for a Section instead of Category. Has a lot of configuration options.

Section List Layout - Similar to Category List Layout, but for a Section. Shows a list of the Categories in the section.