You can edit your book and the book "Details" (the information about your story) as often as you'd like.

To edit your Book, tap the Settings icon, Choose "Edit story" and you'll be launched into the editor where you can edit the story or change the images.

To edit Details, tap the story Settings icon found under the book cover. Choose "Edit Details" and you'll be able to update the information.

Note that public stories that are edited go back into the moderation queue, during which time the book does not appear on your profile, in search, or in the feeds of your subscribers.