Directories-- Web sites arranged by subject
INFOMINE
Librarian's Index to the Internet
Look Smart
Open Directory
Yahoo!

Selected Search Engines-- Search the web:
Ask.com
Bing
Boncoh
Google
Lycos

Metacrawlers-- Submit your search to multiple search engines at once:
Dogpile
Ixquick
Metacrawler

Learn More About Search Engines:
Search Engine Watch