geneanet.org - a free database that indexes all the world's genealogical resources, whether on the Internet or not and whether free or fee-paying. You can use this tool to find out if a piece of genealogical data exists and, if so, where to find it.

ancestry.com - a subscription service which gives you access to many large databases of genealogical data including, U.S. Census data and government birth, marriage and death records.

Ellis Island - a searchable database of every immigrant who passed through Ellis Island.

rootsweb.com - the largest genealogical entity on the Web. RootsWeb has dozens of interactive communities, including the arts and humanities, entertainment, education, health, pets, collectibles, sports, travel, and science and technology. It will also host any number of your own websites for free with no space limitations.

familysearch.org - a free service of the Church of Jesus Christ of Latter Day Saints. Offers a large store of genealogical records, free software to create your family tree, and forums where you can share information with other researchers.