Google has a feature that lets you cut down on the sometimes overwhelming number of results you get from a query. It can be useful if yours is a specialized area of research and you want to exclude irrelevant sites from your search.
Go to the Google main page, at google.com At the top of the page, click on more, and below that on even more. On the page that comes up, under Search, click on Custom Search. On the next page, click on Create a Custom Search Engine. You fill in the name you have decided to give your search engine, its description, the language you want to use, etc., then you paste in the sites you want to search. In my test case, I created a search engine to search banking law research guides from various law school libraries. When I tried out my search engine with a search for "comptroller," it returned three pages, each of which contained my search term.
Google also lets you collaborate, inviting others to contribute to refining your search engine. To access your customized google search, you can use the widget Google provides to add its box to your iGoogle page - it doesn't appear on the Google main page.