The Chronicle of Philanthropy
Calling itself the Newspaper to the Nonprofit World, the Chronicle is a bountiful resource on information about funding sources - though it may take some surfing to find information.
Fundsnet Services Online
Fundsnet Services is a Fundraising & Grants Directory which provides Grantwriting & Fundraising resource assistance to those in need of funding for their programs & initiatives.
Billed as a one-stop resource to find funds for research and training in the sciences, GrantsNet is sponsored by the AAAS and Science magazine.