Just remember, this forum is a "PUBLIC" forum, and the validity of information is not always right, or complete. I myself have discovered "after the fact" that information I provided was either wrong, or incomplete. For rental property, the governing publication is IRS Publication 527 at https://www.irs.gov/pub/irs-pdf/p527.pdf
It covers residential, as well as short term rentals and vacation rentals. I'm of the impression that your situation has the potential to fall under the vacation rental rules based on your comment, "We are going to rent our second home for three months, and on occasion afterwards." I suspect chapter 5 which starts on page 17 would come into play for you. Pay particular attention to the example in the 3rd column on that page, and take note how "ALL" personal use days during the tax year can count against you, regardless of weather or not it was a rental during those personal use days.
