This is one of the most important steps. Compare all benefits to incorporate in this state or another. Please note that although there is a number of "low-tax" jurisdiction in U.S., you will be required to have it registered as a foreign entity in the jurisdiction you plan to do business in.
Choose the type
Choose between Sole Proprietorship, Corporation, LLC, or professional LLC. Most businesses that are not complex by nature go with LLC as it is easier in terms of accounting and provides extra tax benefits. However, if there is a growing number of shareholders and/or you wish to sell your share at a later time you will probably stay with a Corporation. You can apply for S-Corp status to have the tax passed through to the shareholders.
You are required to have a registered agent to receive legal correspondence from the State in the jurisdiction of incorporation. This can be your own address or you can opt to employ one of the numerous agent services on the market.