Yahoo! Search will look for matches to the search text in the Yahoo! directory. Yahoo! is a subject-based directory, so if you're not looking for a specific web site, try to use terms to describe the general subject you're interested in.
For example, if you want a recipe for blueberry pancakes, type the word "recipes." (This is more general, and you're bound to find a category with a number of sites, many of which probably contain a recipe for blueberry pancakes. More choices.) Or, if you're interested in the lyrics to your favorite song, start by typing "lyrics" as a general subject or the name of the musician who sings your song.
Use Yahoo! Search to find web sites organized by subject. Do this by searching for Yahoo! categories and not individual web sites. You'll tend to get more results in categories. However, if you know the site you're looking for, type in the exact name of the site and hit "Search."