By default, all story maps include an Esri logo, with a link to the Esri website, located somewhere in the header or opening section. Also by default the text string "A story map" is included in the header, with a link to the Story Maps website. A good practice, especially if you are authoring story maps that represent your organization, is to replace the Esri default logo, text, and links with a logo and links of your own.
Here's a nice Story Map Tour from the Commonwealth of Kentucky.
If you take a closer look at the header, you'll see a custom logo, tagline, and links have been added.
The logo links to a web site, but what I really like is that the string "A Kentucky story map" links to a gallery of other story maps, created using a group gallery app. Here's the gallery:
This is a good way to let user know about more story maps they might be interested in, from any other story map.
For more information, see Add your organization logo and links to your story maps.