The National Center for Charitable Statistics offers a simplified way for
nonprofits to do their 990 filing online.
Internal
Revenue Service provides nonprofit tax information, publications, forms
and Internal Revenue Service news.
Compliance
Guide for 501(c)(3) - a 20 page Guide for Tax-Exempt Organizations
explains the record keeping, report filing, and disclosure rules that apply
to 501(c)(3) organizations.
Applying
for 501(c)(3) Status - a 16 page guide Tax-Exempt Status is
designed to help prospective charities apply for tax exemption under the tax
law, and helps existing nonprofits understand what this designation means.