Information from the Internal Revenue Service for tax-exempt organizations is available here. This site lists the types of tax-exempt organizations, provides links to IRS forms, offers an FAQ page, and more.
IRS 990-PF's are available at several different websites. Our favorite is the Foundation Center's database. Others include: GrantSmart and Guidestar.
Nonprofit Basics is a site from Nolo Press, a well-known publisher of self-help legal guides. This page links to several useful articles about legal matters of interest to nonprofits.
The Tennessee Secretary of State website has a number of forms of interest to nonprofits. At the Division of Business Services, you'll be able to access the 63-page Nonprofit Corporations Filing Guide and Printable Business Forms which include Forms for Nonprofit Corporations Only and Forms for Both For-Profit and Nonprofit Corporations. At the Division of Charitable Fundraising, you'll find Filing Forms which include Filing Instructions for Charitable Organizations and an Application for Registration of Charitable Organizations.