I'm assuming you are using the online edition of TurboTax Premier. Once you enter all the details of your first rental property, TurboTax will prompt you to enter another rental property if you have any. On the Rental Summary page that appears at the end of entering your existing rental property, you will see Enter New Rental Income for <name> near the lower-right area of your screen. Click this button to enter details of your new rental property.
