Every engine has its own special features. To find out about these various features click on Help, Options, Tips or FAQ (Frequently Asked Questions) at the site of each engine.http://www.yahoo.com (Yahoo - subject classifications)
http://www.hotbot.com (Hotbot - received good reviews recently)
http://www.google.com (Search tips)
http://www.ask.com (Ask Jeeves)
http://www.anzwers.com.au (Anzwers - Australian sites)
http://www.easysearcher.com Compilation of search engines
http://www.northernlight.com (Recent prize winner)
http://www.lycos.com (Lycos - commonly linked to Netscape)
http://www.search.com (A search engine to find search engines)
There are also SUBJECT GUIDES available to assist in your searches:
There are many LIBRARIES that allow searches of their catalogues:http://sunsite.berkeley.edu/InternetIndex/ (Librarians Index)
http://www.clearinghouse.net (Guide to subject guides)
http://www.ipl.org (Virtual public library)
http://ilms.nla.gov.au/webpac/ (National Library of Australia)
http://library.anu.edu.au/search/ (Australian National University)
http://lcweb.loc.gov/ (Library of Congress)