If you are just starting out, you don't need to do anything except register a fictitious name with the state - called a certificate of authority in NC. This is the most basic form of doing business, called the sole proprietorship. You will have your name, then d/b/a after your name for "doing business as." It's cheap and effective. The downside is you get little or no liability protection. However, unless you are hiring people and hanging from high rigs and using heavy machinery, there's nothing that a good liability insurance policy can't handle. The benefits are that it's cheap and there are no tax forms to file come year-end. Your accountant should be able to report your earnings from your photography business together with your individual income tax return.
If you want an additional layer of liability protection, you can form a Limited Liability Company (LLC) with the state of NC. There is an annual fee of $200 associated with this form of entity in NC. As long as you are the only member (owner) of the LLC, it is treated just like a sole proprietorship (described previously) for tax purposes and earnings can be reported together with your individual income tax return. The difference is you pay an extra $200 for the LLC each year.
If you want more tax benefits (usually beneficial once you have an established photography business with additional employees and net earnings of $100,000 or more), then you can look at either creating a corporation (and electing S corporation status) or converting your LLC to an S corporation. This now requires not only an annual fee, but also filing different tax forms, possibly payroll tax forms, state franchise tax and a slew of more costly tax accounting work.
Remember whatever form you take on, you will still need to register for a sales tax ID number and report your tangible property (camera equipment, computers, etc) to the county for Business Property Tax.
PM me if you have questions. I am a CPA in NC and have an office in Raleigh. I'd be happy to help (free of charge, too.)
Alex