01(c) organization or simply "a 501(c)" is an American tax-exempt, nonprofit corporation or association. Section 501(c) of the United States Internal Revenue Code (26 U.S.C. § 501(c)), provides that 28 types of nonprofit organizations are exempt from some federal income taxes. Sections 503 through 505 set out the requirements for attaining such exemptions. Many states refer to Section 501(c) for definitions of organizations exempt from state taxation as well.
Setting up a charitable organization involves complying with both state and federal law. You'd form your non-profit or charitable entity by filing with the Secretary of State in Olympia. There are forms and other information on the Secretary of State's website you can look at (www.sos.wa.gov). There is a subsection online devoted just to charities. Obtaining the tax exempt status is done through the IRS. I usually suggest getting help from a CPA to handle the federal tax portion. Hope it all goes well for you.
This response is for general purposes only, is not legal advice and does not constitute an attorney client relationship with the questioner.