The best way to really understand a prospective funder is to consider the grants that the organization has given to other nonprofits.
Published guidelines may say one thing, but the grantee list tells the real story.
Once you have a specific foundation in mind, you need to learn how to read this foundation’s IRS form 990. Foundation websites are great for giving you the latest grant application guidelines, but they don’t begin to give you the depth of information as the Form 990-PF Return.
The 990 will give you a list of the other nonprofit organizations that the funder has supported, and the specifics of the grants they gave (amount, and sometimes brief project descriptions).
Analyzing this list will help you to know if you have a chance of being funded.
Free databases of 990s:
With either website, you can simply enter the name of the foundation to link to their annual 990s.
Need more help?
Check out the free e-guide How to Read the New IRS Form 990 by Peter Swords of the Nonprofit Coordinating Committee of New York.
A detailed article about how to read 990s is available here.