Actually, a great resource is the new Nonprofits Subject Gateway, created by Business Librarian Shana Gass. This resource lists resources for finding charitable giving statistics, charity tax filings, and grant applications.
Two other things of note:
- The Mediamark (MRI+) database does have some information on charitable contributions so you can find out what media contributors are more likely to use. Oddly enough, that info is listed under the category of "Contributions to Public TV/Radio" so it is easy to miss.
- The Foundation Center has released a new GrantSpace site. This site offers lots tools to help novice grantseekers navigate the application process.