The Emails sent report shows how many emails in total were sent for this particular campaign. Drilling down on this report will display all the email recipients who were sent this campaign.
Clicking on the Export button will display a drop down menu that will allow you to export a contacts list out to a CSV file or you an Address Book from these recipients.
To return to Reporting overview screen, use the More Reports button and click Campaign overview. The drop down also displays a menu from which you can select other report types as shown below.