Press to select Settings from your iPhone SpringBoard.
Press to select Mail, Contacts, Calendars from the Settings Menu.
Press Add Account..
Select Microsoft Exchange from the list of account types
Enter your full hotmail email address for the Email and Username fields then fill in your password. Press the Next button at the top right of the screen to continue.
Input m.hotmail.com as the server address and press the Next button.
Use the switches to select which items you would like to sync and press the Save button.