Argus Clearinghouse
This site describes itself as the "Internet’s premier research library". The topical guides are selective, definitely not all-inclusive and ratings are part of what makes this site special. Easy to use.
http://www.clearinghouse.net/

CINCH™ (Conputerized Information Network for Cincinnati and Hamilton County)
Connects to information about the resources and programs of the Public Library of Cincinnati. Includes links to electronic resources, a "kids’ site", user information, Internet resources, etc. Access to some resources requires a valid PLCH patron card.
http://plch.lib.oh.us/

Internet Public Library
The IPL provides kids, parents and teachers with a vast collection of educational materials throughout the world. Parents and teachers seeking age-appropriate publications will benefit by the material presented here, while kids can peruse over 7700 online texts.
http://www.ipl.org

Library in the Sky
Containing over 7,000 links to some of the best educational resources on the Internet, The Library in the Sky guides teachers, students, parents, librarians, and members of the community on their journeys through cyberspace.
http://www.nwrel.org/sky/

Library of Congress
A vast resource, "the Library's mission is to make its resources available and useful to the Congress and the American people and to sustain and preserve a universal collection of knowledge and creativity for future generations". http://www.loc.gov/

OHIOLINK
Ohiolink is a consortium of Ohio's college and university libraries and the State Library of Ohio. OhioLINK offers access to more than 24 million library items statewide. It also provides access to 67 research databases, including a variety of full-text resources.
http://www.ohiolink.edu