Choose a name for your nonprofit corporation and create an official operating agreement. In your operating agreement you should include a name, mission, board of directors, officers, & other important information that will help keep your clients happy and your non-profit running smoothly. Write a mission statement and a business plan for your non-profit. These documents will help you choose your name, how to operate your nonprofit, and what products or services to offer. File your Nonprofit Articles of Incorporation with the state government. Make sure to include a Memorandum of Organization & Bylaws. Start your business license application and apply for a tax ID number from the IRS. For more info see this.
The final steps are to prepare and distribute your Annual Statement of Operations, Annual Reports, Annual Financial Statements, & other Non Profit reports, which will show your nonprofit status, donations received, financial status, balance sheet, profit & loss statement, and tax returns. The last step is to register your nonprofit with the IRS as a tax-exempt, exempt status, or an S-Corp. Once you do these six steps, you can start planning how to take your nonprofit beyond the name, mission, & business plan.