Incorporating a nonprofit is done at the state level. A formation document, usually called Articles of Incorporation, are prepared and filed with the state's division of corporations.
Most states provide a boilerplate, or template document, the "blanks" of which can be completed for purposes of incorporating. It is crucial to point out, however, that very few templates meet Internal Revenue Service requirements for obtaining 501(c) status. If your intent is to seek federal tax-exempt status as a 501(c), it is advisable to seek the assistance of someone familiar with federal requirements.
For more information, see our Nonprofit Startup page.