Summarize:

iTunes will automatically launch upon recognizing your device.   ” Selecting the “All calendars” option will sync Outlook with all the calendars on your iPhone, whereas choosing “Selected calendars” will allow you to select one or more calendars you want synced on your iPhone. ” iTunes will start syncing Outlook with your iPhone.  Outlook will now be synced with your iPhone.
Connect your iPhone to your computer using a USB cable. Click on the name of your iPhone in the left sidebar of iTunes. Click on “Info” at the top of your iTunes session. Click on “Sync calendars from,” then select “Outlook. Select either “All calendars” or “Selected calendars,” based on your preference. Click on “Apply. Wait for iTunes to inform you that synchronization is complete. Disconnect your iPhone from your computer.