I'm not a 100% sure, but I think if you filed taxes for it the previous year as a rental property, it would be treated as a rental propety this year and you would use Schedule E.
If you have a substantial profit you might be better off treating as a residential property in order to take advantage of the capital gain exclusion. If you lived in it for 2 out 5 years you could treat as residential property, but you need to read the IRS rules. FYI, I've found that folks at fairmark.com forum give some of the best tax advice on the internet, lots of CPAs, current and form IRS employees.