Obituaries can be gold mines to genealogists.  They may list birth and death dates, cause of death, maiden names, grandparents, children, spouses, in-laws and stories!  Unfortunately, not everyone has an obituary, and if one does exist, it may not be easy to find. Sites like Ancestry.com and HeritageQuest, both of which the library subscribes to, are helpful.  However, they aren't comprehensive.  The following is a list of free sites worth searching for obituaries (in no particular order):

1. Fultonhistory.com - Search over 29,140,000 historical newspaper papers from the US and Canada.
2. Legacy.com - Covers more than 1,500 national and international newspapers (US, Canada, Bermuda, New Zealand, Ireland, England, Scotland, Wales and Australia) from February 2001 to the present.
3. Tributes.com - Covers more than 95 million records dating back to 1936; information comes from funeral home partners and the SSDI.
4. Ancestorhunt.com - Links to free obituary databases across the US.
5. Boston Public Library Globe and Herald Obituary Search Engine - Contains obituaries that appeared in the Boston Evening Transcript, Boston Globe and the Herald/Herald American between 1932 and 1941, and between 1953 and 2010.
6. Genealogyintime.com - An all in one search engine good for locating obituaries and a lot more; gives monthly updates on what records have been added to other online sites and databases (not comprehensive).
7. ChroniclingAmerica.loc.gov - Search some of America's historic newpaper pages from 1836-1922.
8. America's Historical Newspapers - This is a fee-based site that can be accessed by Massachusetts residents through the Boston Public Library's website.  It covers many early American newspapers from 1690-1922.  You'll need a Boston Public Library card which you can get online (if you are a Massachusetts resident).