BenefitsCheckUp
A customizable site to "screen for federal, state and some local private and public benefits for older adults (ages 55 and over)." Identifies "programs that a person may be eligible to receive," and "provides a detailed description of the programs, local contacts for additional information (typically the addresses and phone numbers of where to apply for the programs), and materials to help successfully apply for each program." From the National Council on the Aging.

GovBenefits.gov
Sponsored by 10 federal agencies, this site helps you determine what benefits you may qualify for. Offers several ways to search its database (such as by completing a questionnaire) and includes both federal and state resources.

Grants.gov
Provides access to a database of federal grants, searchable by subject category, keyword, and agency name. Applicants may apply online.

MealCall.org (Meals on Wheels Locations)
An index, by state and city, of meal-delivery services. (Note: Includes paid ads.)

Nutrition Assistance Programs: (U.S. Department of Agriculture, Food and Nutrition Service)
Information on all types of food assistance programs, including food stamps.

Social Security Online
Official web site of the Social Security Administration.

Social Security Online: Disability Planner
A guide to the federal government's disability programs.

Subsidized Apartment Search
"The housing choice voucher program is the federal government's major program for assisting very low-income families, the elderly, and the disabled to afford decent, safe, and sanitary housing in the private market." This site provides a searchable database of subsidized housing units, also known as Section 8 housing. Search by location (state, county, city), housing type, and number of bedrooms. From the U.S. Department of Housing and Urban Development (HUD).

U.S. Administration on Aging
A major resource providing links to federal agencies that offer assistance. Covers such topics as financial planning, health insurance, nutrition, housing, and more.

U.S. Department of Veterans Affairs
Information on benefits available to United States veterans.