Foundation Center by Candid
Foundation Center is a subscription plan offered by Candid (formerly known as Guidestar), which has an exclusive data sharing arrangement in place with the Internal Revenue Service. Although this resource does require a paid subscription, public charities have found it useful to identify and research quality funding prospects, as well as available grant information.
California Community Foundation
Grants.gov is a very useful resource for the pursuit of available federal funding. The Grants.Gov site allows nonprofit applicants to complete a profile to evaluate eligibility for current grants. Once complete, you can utilize the Grant Search function which narrows done relevant grants for which your organization qualifies. Conveniently, all application materials are completed directly within your profile created on the site.
California Attorney General Registry of Charitable Trusts
The Office of the California Attorney General posts grant opportunities on a periodic basis that are awarded on an annual or semi-annual basis.
Social Impact Guide
Social Impact Guide posts period grants available for funding to social enterprises across the United States. A list of grants currently open to social enterprises can be found here.