I don't know much about leasebacks, but I would think it would be treated as any other rental property. Offhand, I can't think of why it would be treated differently.
If that is the case, you would report the income and expenses for those 5 months on Schedule E. As Carl said, don't bother entering the house as an "asset" because you can't take depreciation if it is "placed in service" and taken out of service as a rental property in the same calendar year. As for how to enter the rest of the expenses into TurboTax, Carl is the expert.
However, the Home Sale Exclusion would be reduced.
@Carl : The rental period would be considered "nonqualified use" because it was used for personal purposes after the rental period after 2008.
For simplicity let's say you had rented it out for exactly 6 months, and then used it as your principal residence for exactly 9.5 years, for a total ownership of exactly 10 years (the actual calculation uses days). In that scenario, 95% of the gain would be excluded (9.5 years divided by 10 years). So if you had a profit of $100,000, your Home Sale Exclusion would be 95% of that ($95,000) and you would owe long-term capital gains on $5,000 (taxed at 0%-20%, but it could affect other things on your tax return, especially if you have high income).