There are several steps required to legally create a corporation. The first is filing a short document called "articles of incorporation" with the corporations division of your state government. (Some states refer to this organizational document as a "certificate of incorporation," a "certificate of formation," or a "charter.") You'll have to pay a filing fee that ranges from about $100 to $800, depending on the rules of the state where you file. This document contains basic information such as:
When forming your corporation, you must also create "corporate bylaws," a longer document that sets out the rules that govern your corporation, including decision-making procedures and voting rights.
Finally, before you start doing business, you must hold an initial meeting of your board of directors to take care of some formalities, and you need to issue shares of stock to the initial owners (shareholders).
For more information, see Nolo's article How to Form a Corporation.
If you need legal advice for your business, talk to a lawyer.