If you plan to form a business, there are a few things you need to do first. You'll need to decide what kind of business you're going to be, first. Are you planning a partnership, S Corporation, cooperative, Limited Liability Company, corporation or sole proprietorship? Each has its own benefits that you'll want to consider; the U.S. Small Business Administration has information on the types of ownership, but to focus on just one, look at the LLC.
An LLC has to be different from all other LLCs in your state. You can choose a name, and that name should have "LLC" after it. You can't use restricted words, so you may want to discuss with your attorney which words to avoid in your business's name.
You'll need to look into filing the Articles of Organization, which legitimizes your LLC. Following that, you will want to create an operating agreement, even if your state doesn't require it. The agreement focuses on the rules and regulations of your business, so it can operate smoothly, even if you have more than one person working at a high level in the organization.
Other things you'll need to consider having include licenses and permits, employees and marketing assistance. You may need to formally announce your business in the local paper, if your state requires that step. Doing so can help you market your business and alert others to the opening, so it's a good idea to publish and announce your business in any case.
Our website has more information on opening a business, no matter what type you're interested in.