To turn the feature off - or relocate the Reading Pane - open Settings in Outlook and scroll down to Reading Pane.
If you typically use Gmail, you'll be more familiar with a setup with no reading pane. It makes for quick scrolling and less clicking when you've got a lot of messages to get through. The reading pane lets you read a selected message without leaving your inbox. In Microsoft Outlook, the basic set up splits your screen into three columns: the list of folders such as Inbox, Sent and Junk Mail the Inbox itself and the reading pane.
