I would check YOUR states regs/laws. These will vary from state to state, for instance here in Iowa its a one time filing fee of ( can't recall but I believe) $50 to register and be recognized as an LLC, incorporation requires yearly renewal, both require articles of incorporation be filed with the Sec. of State.
Here is the link for Ohio Sec. of State website, really shouldn't be that difficult of a task to handle yourself. I met with my CPA to gain more insight from a tax standpoint what business entity would best serve our purposes. This year was extremely good, over the next couple of years we will make the determination whether to incorporate or not.