You can publish a book from two locations:
1. Inside the editor: tap the Menu in the bottom-left corner and select "Publish".
2. Your Unpublished folder (the link is on the left rail of your Dashboard). Tap the Settings icon found beneath the cover on the bottom-right corner of the white card. Select "Edit Details" from the popover menu.
On the "Details" form you'll find:
Change cover: Don’t like the cover? Change it.
Change title: Same as above—change it if you want.
Summary: Your story’s “flap copy” or synopsis.
Categories: How we organize your stories. Choose 2.
Tags: How you organize your stories. Add as many as you'd like.
Wrtiten for: Who’s the story most suited for?
Privacy: Public or private option.
Delete: Don’t like it? Throw it away and make another.
Longform (multi-chapter) books also include:
Chapter type ("This is"): Select if this is a standalone, first chapter of a book, part of an existing book, or last chapter.
Chapter note: Teaser copy that appears in the story margin and main feed/timeline.
Chapter title: Story lead-in, mini-summary, etc that appears above the story.
Tap "Publish" at the bottom of the form when you've added your details. Done!
Note: You can change any of these at any time as often as you'd like.