To view the performance report of a specific campaign, access it under the Campaigns tab after delivery. You will immediately see details such as who the campaign was sent to, clicks and open rates, emails bounced, spam complaints, and unsubscribes. If you added the Social Media Toolbar - stats are also available for Facebook and Twitter shares.
You may also see more specific details such as who clicked on what and even a detailed heatmap of the campaign's activity, available on the left hand menu.