Yahoo also has a considerable advantage in having humans make decisions about content, which can eliminate some very peculiar matches made by robot search engines. This one uses human guides to categorize sites in their fields of expertise. It is fast, clear, and often uncovers links that single search engines miss. DogPile is another meta engine you might try or try SavvySearch. In particular, you need to know when to use and to connect words in a phrase and whether or not to use parenthesis or quotation marks to set off descriptors.
Many search engines support boolean operators.
Look for a popup menu somewhere below the search field. Click on the box and click on the number of results you want. Most search engines default at 10 links. This means you'll receive results in batches of 10 unless you specify otherwise. Some search engines don't allow you this option.