An attorney is always the best idea. Make sure it is a copyright/contract guy or entertainment attorney. the best place to ask about them is if you have an arts organization in your city or state that can recommend one.
My own attorney is an entertainment attorney plus a tax attorney. He is licensed to practice law in the State of Washington. Not knowing where you're located I can't recommend him for outside of Washington, although I know he's good about people contacting him and letting them know what, or if, he can do anything for them.
Most attorneys will have a preliminary meeting with you to find out what you need and want and how they can help you where they will tell you what their rates are, how they bill etc. (please note, I'm operating under the assumption that you're one of the younger members here who has not worked with an attorney before. If you have I apologize profusely, but I don't want to assume you have worked with one before and not relay information you might need.)
Again operating on the assumption you haven't worked with an attorney before the more organized you are the shorter your time with them and therefore the lighter the bill. Tax deductions have changed over the years so I'm not sure how much of an attorneys fees are deductible anymore (if you file a schedule C for your taxes... assuming you're here in the States).
and you're right, this all is a LOT easier with an attorney not only to do the work but to consult with and give you the information you need to make an informed decision.