These are the basic requirements:

Organizing a nonprofit organization should include a number of operational duties for the survival of the organization. At a minimum, these items should include developing a strategic plan, case statement, articles of incorporation, budget, and set of bylaws. 

1. Check with your local state offices for business development to determine their requirements. Each state differs in their requirements. Often the contact is the state attorney general's office. 
2. Check with the Federal IRS offices to file the necessary forms. You must first determine what type of entity classification you will use. Not all will have tax-exempt status. The most common form is the 501c3, tax exempt organization, organized for charitable purposes. If you have questions, consult an attorney after you have read the requirements of each option. IRS publication #557, Tax Exempt Status for Your Organization is very helpful. It explains the application procedures and forms required. (See below)
3. Depending on your organizing requirements, you may need to develop a set of bylaws to guide the operations of your organization, and a set of articles of incorporation. The bylaws are extremely important. They should provide instructions as to the selection, responsibilities, and continuance of board members, membership requirements, officers, deposits, committee structures, notices, and other personal and insurance questions as they relate to the operations
   of the specific nonprofit business. 

The Articles of Incorporation name the organization, its location, the organizing purposes, liability, and include the dissolution requirements of the corporation. 

• Sample Articles of Incorporation.   Courtesy of Management Assistance Program for Nonprofits (MAP).  See also the examples of bylaws provided on "How to Start a Theatre Company" home page.
• For a detailed overview of the incorporation process, see the website of the Management Assistance Program for Nonprofits (MAP).
• For specific information on creating bylaws and articles of incorporation, we recommend the book, Theatrically Speaking, available from Texas Nonprofit Theatres, Inc. 

Non-profit status 
Federal-United States (Internal Revenue Service). 

Charitable, religious, educational, scientific, literary, etc. organizations that meet the requirements of § 501(c)(3) are exempt from federal income tax.

To be recognized as a Nonprofit Charitable Corporation under Section 501(C) of the US Internal Revenue Code, a corporation must file for an exemption. 

If you plan to apply for tax exempt status, you might want to start with the IRS website.

• Application for Recognition of Exemption
  How to apply for recognition of exemption as a  501(c)(3) organization.
  • Package 1023 (Rev. June 2006)
    Application for Recognition of Exemption Under Section 501(c)(3) of the Internal Revenue Code
  • Publication 557 (Rev. July 2001)  Contents Introduction .. 2 Chapter 1. Application, Approval, and Appeal Procedures .. 2 Application Procedures .. 2 Forms Required .. 2 Required Inclusions .. 3 Miscellaneous
  • Form 1023: Application for Recognition of Exemption Under Section 501(c)(3) of the Internal Revenue Code
  • Form 1024: Application for Recognition of Exemption Under Section 501(a) for Determination Under Section 120 of the Internal Revenue Code
• Filing Requirements
  A brief description of the annual filing and disclosure requirements for charitable organizations.
• Private Foundations
  Charitable organizations are considered private foundations unless they meet certain requirements. A brief explanation of these requirements and the effect of private foundation status when these requirements are not met.
• Unrelated Business Income Tax
  Charitable organizations engaged in an unrelated trade or business are subject to the unrelated business income tax.
• Contributions
  A brief description of the disclosure and substantiation requirements for contributions to charitable organizations
  • Tax Information for Charitable Organizations

Note: the above information does not constitute legal advice. You may wish to seek legal counsel.