General Research

Ancestry.com
http://www.ancestry.com 

FamilySearch
http://www.familysearch.org

FindMyPast
http://www.findmypast.com 

Fold3
http://www.fold3.com

Google
http://www.google.com

Google Blog Search
http://blogsearch.google.com

Google Groups
http://groups.google.com

Google Newspapers
http://news.google.com/newspapers

Google Scholar
http://scholar.google.com

Internet Archive
http://www.archive.org

Mocavo
http://www.mocavo.com

MyHeritage
http://www.myheritage.com

NARA
http://www.archives.gov

Roots Web Search Thingy
http://sitesearch.rootsweb.ancestry.com/cgi-bin/search

US Gen Web
http://www.usgenweb.org

US Gen Web Archives
http://usgwarchives.org/index.htm

World Gen Web
http://www.worldgenweb.org