Librarians' Internet Subject Guides
(And some other library-associated resources.) Well-selected and organized guides to information on the Internet. These can be more useful than commercial WWW indexes like Yahoo, because they are selective and done by information professionals.
IPL: The Internet Public Library I know I have this linked elsewhere, but it bears repeating....
The Argus Clearinghouse A list of lists in many areas, put together by people interested in those areas.
Michigan Electronic Library A good one--Yahoo-like in its comprehensiveness, but not commercial in its focus.
Berkeley Public Library
The LSU Webliography
The UCR Infomine
The Mansfield Cybrarian
University of Houston Libraries
National/International Libraries: Library of Congress
Queensland, Australia Dept. of Ed. Virtual Library: Includes an Internet tutorial.
Portico: The British Library's Web site, with information about the BL and examples from its collections.
The National Library of Canada
University Library of Bergen, Norway: Mostly in Norwegian but nicely organized. American Library Association Good lists of links and information about award-winning books. Public Libraries Across the U.S.
Literally. Make sure your telnet utility is linked in to your Web browser. Find that hard-to-find book and then get your local library to order it....
Parts of this list are from the Internet Librarian column by Karen Schneider in American Libraries.