Let's use this discussion to post links of valuable (and FREE) genealogical data repositories. Please add: my list is mostly American and doesn't include Wikipedia, because y'all know about Wiki already. :)
First stop in locating US vital records:
http://www.familysearch.org/eng/default.asp
and their beta site:
http://fsbeta.familysearch.org/
I have found contradictions and errors in their records, but understand that many vitals are based on "reporters" from the days before government records.
http://wc.rootsweb.ancestry.com/
The quality varies enormously, from unverified GEDCOM to very well documented. Lookups are really fast and easy and include the SSDI death index:
http://ssdi.rootsweb.ancestry.com/
http://fmg.ac/Projects/MedLands/
A prosopography of medieval European noble and royal families
Considered the most accurate site available. Not for the faint of heart: it's quite scholarly.
The site of record for the European royal families and on the British Peerage
Over the past century, the Society’s research provides a strong foundation for the study of New Sweden Colony (1638-1655), the short lived effort by Sweden to claim a stake in colonial America. After 1655 the Swedish flag no longer flew overheard, but the Swedish and Finnish colonists remained as the majority population in Delaware, Southeastern Pennsylvania and Southern New Jersey under successive Dutch and English rulers. They lived with a considerable degree of self government until the arrival of William Penn and the flood of several thousand English Quakers ended the so-called “Swedish Nation on the Delaware” (1655-1681).
Already I'm fascinated!
The Historical Marker Database
http://www.hmdb.org/
A categorized, searchable database containing historical markers and commemorative plaques from across the United States.
JewishGen - The Home of Jewish Genealogy
http://www.jewishgen.org/
Provides a wide range of resources including databases, familyfinder, articles, societies, projects and discussion groups. Databases include "shtetl finder" and "burial records"
Every book that's ever been published can be found in a library, here:
Includes instant "citation makers" and links to googlebooks and amazon.com.
The USGenWeb Project consists of a group of volunteers working together to provide Internet websites for genealogical research in every county and every state of the United States. The Project is non-commercial and fully committed to free access for everyone.
Includes will, cemetery and census transcription files.
Many people know the National Archives as the keeper of the Declaration of Independence, the Constitution, and the Bill of Rights. But we also hold in trust for the public the records of ordinary citizens—for example, military records of the brave men and women who have fought for our country, naturalization records of the immigrants whose dreams have shaped our nation, and even the canceled check from the purchase of Alaska ...
http://chroniclingamerica.loc.gov/
Welcome to Chronicling America, enhancing access to America's historic newspapers. This site allows you to search and view newspaper pages from 1860-1922 and find information about American newspapers published between 1690-present. Chronicling America is sponsored jointly by the National Endowment for the Humanities and the Library of Congress as part of the National Digital Newspaper Program (NDNP).
http://www.themayflowersociety.com/
More than one hundred years ago, a group of descendants of the Pilgrims who sailed on the Mayflower in 1620, saw the need for a national society to honor their memory. The intention was to remember these Pilgrims who established Plymouth Colony, in what was then called the northern part of Virginia.
Today there are tens-of-millions of individuals descended from these brave souls. It is the goal of The Mayflower Society to join together people who share this heritage and to carry on the memory of our Pilgrim ancestors.
