There are some informative and authorative web sites discussing tax returns for tax exempt organizations often referred to as non-profits. Public Law Center, The Nation’s Largest Pro Bono Law Firm ‘s Form 990 Policy Series Memoranda presently includes Memoranda on Comprensation, Conflict of Interest, Conservation of Easements, Document Retention and Destruction, Form 990 Review, Fundraising, Gift Acceptance, Independent Governing Body, Investment, Mission Statement, Public Disclosure, and Whistleblower. Along with the Memoranda are reasons for adopting the policies, with references to applicable statutes, regulations, and Procedures. Additional Memoranda on Joint Ventures, Endowments, Consistent Operation of Chapters/Affilliates/Branches, and Financial Statements/Audit Policy are intended for future publication. Here is a link to the How to Read the IRS Form 990 based on the 2010 IRS Form 990. The IRS Forms 990 and instructions for 2012 are here.