Yahoo is a subject directory which has its Internet sites organized by
subject, and is usually maintained by humans instead of software. be
specific and use keywords.
Yahoo
Google uses software to go out into the internet to index information from
sites which is then added to its database. Be specific and use keywords.
Google
Alta Vista is a directory based search engine and allows you to limit a
search within the USA or other countries.
Alta Vista
About is not really a search engine, but does have human guides who go out
and gather the best web sites on a particular topic.
About
The LII Mission Statement: The mission of Librarians' Index to the Internet is to provide a
well-organized point of access for reliable, trustworthy, librarian-selected Internet resources, serving
California, the nation, and the world. (from the About page)
Librarians' Index to the Internet