If you are writing grants for an organization in Maine, you will want to make use of the Maine Philanthropy Center. This is a regional association of grantmakers working to promote philanthropy and to increase its impact in Maine. The members include private family and independent foundations, community and public foundations, and corporate foundations and giving programs. You will find membership benefits, programs and events, and resources for grantmakers and nonprofits. Their site also houses the common grant application form, which is worth studying and answering for practice. Their database of potential funding partners is easy to use and while it is linked to the Foundation Center’s massive database, it frequently has details about local funders that the big database misses.
Maine Association of Nonprofits (MANP) is a membership organization offering professional skill development programs, affordable healthcare, and benefits plans, discounts on related programs and services and advocacy resources, and is part of a national network of state associations. MANP has also added grant seeking resources for members using grantstation.com.
The Maine State Library maintains a page related to grants here.