Obituaries are an incredible resource! They not only tell birth and death dates for your ancestor, they usually also list family members. Sometimes there is even a photograph attached. If you know where your family member died, you might be able to find the obituary online if it is fairly recent. Some newspapers charge for online information. You can also get in touch with the library in the town or county where your ancestor died, and they may have online information, or they may provide a copy of the obituary. Some libraries charge a fee. Here is an example of a library that provides tantalizing skeletons of information for free. http://www.rbhayes.org/hayes/index/
Here is a website for Canada http://www.islandnet.com/~jveinot/cghl/cemetery.html
Some other resources:
http://surnamearchive.com/obits/1obits.htm http://www.ancestorhunt.com/obituary_search_engines.htm
http://www-personal.umich.edu/~cgaunt/obits.html http://www.genealogypitstop.com/
This is not exactly a free site, but the snippets are good.