Information requires an internet connection (either through Wi-FI, cellular, etc).
This will display the book overview, a link to the google preview (if available), edition information, and a list of subjects. The Google previews are only available from the Google website, so pressing this link will take you to Safari and exit this application.
Goodreads Reviews (Goodreads Reviews must be turned ON under Settings)
This will display a list of reviews found in Goodreads. Select a review to display the entire review.