All of these search engines will yeild different results givien similar search criteria. This is because each search engine is orgranized differently and keys off of different information. If there is too much information for you as a result of a search, look more closely at the advanced search interface many of these search engines give you. If you follow their instructions, you can effectively narrow your search. Yahoo is the first and most popular search engine.
Information is arranged alphabetically under a topic tree.
You can start in Yahoo not knowing exactly what you are looking for and start with 14 high level topics. Each one breaks down into more and more subtopics. Eventually you find references to the web pages you are looking for. Of course, you can also enter keywords into the search window and let it look. Cnet, Galaxy, Infoseek Lycos and Northern light are similar in the aspect that a search tree exists.