GENERAL SITES:

• Librarians' Internet Index:  This is an excellent subject directory to quality sites on the Internet.  Sites can be accessed through a subject tree or through a keyword search.
• Digital Librarian: "A librarian's choice of the best of the Web"
• The WWW Virtual Library:  "The WWW Virtual Library (VL) is the oldest catalogue of the Web, started by Tim Berners-Lee, the creator of HTML and of the Web itself, in 1991 at CERN in Geneva. Unlike commercial catalogues, it is run by a loose confederation of volunteers, who compile pages of key links for particular areas in which they are expert; even though it isn't the biggest index of the Web, the VL pages are widely recognised as being amongst the highest-quality guides to particular sections of the Web."

DEEP WEB SEARCH TOOLS:

• INFOMINE:  Scholarly Internet databases
• CompletePlanet:  Links to over 70,000 searchable databases and specialty search engines

GOVERNMENT SITES FOR RESEARCH AND STATISTICS:

• USA.gov: The U.S. government's official Web portal allows you to search for information found on any of the federal .gov sites from one page.
• science.gov:  "Science.gov searches over 36 databases and 1,850 selected websites, offering 200 million pages of authoritative U.S. government science information, including research and development results."