One of my requirements for ILS 501 was a search paper. In preparing for this paper, I discovered many "new to me" search sites as well as a few sites of general interest. Here are several which I found useful. Clicking on the logo will take you to the site.
Google Scholar is a great site for locating Journal Articles about a particular subject.
Mamma.com is a fantastic MetaSearch Engine. It was helpful in narrowing search results.
Google has made itself into the most used search engine worldwide. Even though it returns a high number of results, it is an excellent starting poing for many searches.
Microsoft's new search engine - pretty and useful all at the same time!
Search Engine Watch is full of information from search engine optimization to key word assistance to tutorials and articles about the world wide web.