Can anyone explain what I am supposed to enter in "amount not on principal residence" under the property tax section? I am not aware of where to find this information

[SharonD007]

You would enter the amount of property tax that you paid for a second home if you have one.  If you don't have a second home, leave it blank.  Don't enter property taxes that you paid for a rental property because that information goes on a Schedule E.

There's a cap on the total amount of taxes (state and local income taxes, personal property taxes, and real estate taxes) of $10,000 ($5,000) if you are filing Married Filing Separately (MFS).

For more information, refer to the TurboTax article Claiming Property Taxes on Your Tax Return.