This search tool is great for beginners and subject browsing.
Indexes more than 1 billion URLs. The search page is very clean and easy to use.
Altavista has powerful search capabilities. Take a look at the search tips.
"INFOMINE is a comprehensive virtual library and reference tool for academic and scholarly Internet resources, including Web sites, databases, electronic journals, bulletin boards, listservs, online library card catalogs, articles, directories of researchers, and other types of information."
This metasearcher allows you to limit your search to specialized databases and search engines.