You can only deuct interest and real estate taxes on your Principal Residence.
You should consult with your accountant regarding allowable deductions for 2nd Homes and Investment property such as depreciation.
It depends upon how much of the time you intend to use it for personal use. If it is an investment property it would be best to talk with your accountant or tax advisor. I own investment property and I am unable to deduct mortgage interest on any loans directly made to purchase the property. I have used home equity loans on my personal residence over the years to purchase my investment units and that mortgage interest was fully deductable from my Fed. Income Taxes. Again, seek the advice of a good CPA or tax accountant.