When to start using a CPA?

[Bienes Raices]

My lawyer recommended talking to a CPA about my rental properties. I've never used one before (I've done the itemized deductions by myself once--last year, with Turbo Tax--for my rentals).

Do you typically have the CPA actually prepare the tax return, or just use him or her as a sounding board for tax questions? Would it better or more cost effective to go to an enrolled agent?