For Outlook for Office 365, Outlook 2016, Outlook 2013, Outlook 2010, Outlook 2007
Newer Versions of Outlook
See Microsoft article Print a calendar showing appointments and meetings for details.
Outlook 2010
When printing Calendars you are given several options. In order to Print use either the shortcut Ctrl+P or from the ribbon choose File>Print.

When given the print options screen you will see you are given six different options as to how you would like the Calendar view to be printed. By clicking on each of these you will be given an automatic print preview in the left hand view pane.