AARP is a nonprofit membership organization dedicated to addressing the needs and interests of persons 50 and older.  The main topic areas on their site include member services and discounts, computers and technology, health and wellness, learning, legislation and elections, life answers, money and work, policy and research, travel and leisure, and volunteering. 
 

Elderhostel :  http://www.elderhostel.org

Elderhostel, Inc. is a non-profit organization that provides high-quality, affordable, educational adventures for adults who are 55 and older. 
 

FirstGov for Seniors :  http://www.seniors.gov

Provides senior citizens, and anyone who works on their behalf, a single site where they can access government services and information.  Includes access to government agencies, information about social security benefits, health and nutrition, taxes, consumer protection, and more. 
 

Medicare :  http://www.medicare.gov

The official U.S. government site for Medicare information.  Includes Medicare basics, plan choices, helpful contacts, and Medicare publications. 
 

Nursing Home Compare :  http://www.medicare.gov/NHCompare/home.asp

The primary purpose of this tool is to provide detailed information about the performance of every Medicare and Medicaid certified nursing home in the country. Includes information about individual nursing homes, including the number of beds and type of ownership, as well as information about the residents of the nursing home, nursing home inspection results, and information about the nursing home staff.  Information in this database should be interpreted carefully and used in conjunction with other sources, as well as a visit to the nursing home. 
 

SeniorNet :  http://www.seniornet.org/php

The nonprofit SeniorNet provides adults 50+ access to and education about computer technology and the Internet to enhance their lives and enable them to share their knowledge. 
 

Senior Providers :  http://www.seniorpro.com

Senior Providers is a directory of services and housing specifically for Florida seniors.  Included is information on assisted living, independant living, nursing homes, Alzheimer's facilities, home health agencies, geriatric care managers, guardianship services, hospice care, continuing care communities, adult daycare, elder law, and more.