The Foundation Center: Founded in 1956, the Center is the nation's leading authority on philanthropy and is dedicated to serving grantseekers, grantmakers, researchers, policymakers, the media, and the general public.

http://foundationcenter.org

Non-Profit Guides:
Links to non-profit and charitable organizations; proposal writing tools, sample proposals
http://www.npguides.org/links.htm

Foundations On-Line:
A Foundation directory and search tool.
http://www.foundations.org