i have two 3-family buildings, one that i have owned since february 06 and the other i am closing on in a month.
if i deed them to an llc in december, would this benefit me for my tax return for this year?
deeding them to an LLC is not a tax strategy, it is an asset protection strategy.
since the income is already passive to you (no se tax) there is no significant tax benefit from putting them into an LLC taxed as anything other than a corporation, which likely has a lower tax rate. And if the properties have significant cash flow that you want to take out, corporate taxation may actually be worse for you, since dividends from the LLC/Corp will be taxed again and salary is subject to FICA.
at any rate, moving them in december will not give you what you’re looking for: the LLC only takes revenues/expenses for December.