Legal advice is invaluable along the road to running a successful business. A good accountant can help you determine the tax consequences of the business entity you choose. In addition, an accountant may be able to advise you regarding the state in which you should set up your business. On the other hand, such a move could actually increase your tax burden if you don't understand all the implications. They'll make sure the name you've chosen is still available, register your business, help you request the correct tax status, and handle the added paperwork if you decide to register your business in another state.
Fees vary, but they're generally in the several hundred dollar range.
Whether or not you seek professional help, take your time as you choose the right status for your business. The right decision could mean significantly more money in your pocket and, in some cases, much less red tape.