You might already know about Firefox's custom keywords, which let you assign keywords to your favorite sites through the Bookmark Manager. But even more convenient is the ability to quick-search Web sites by..
typing a short keyword followed by a search term into the address bar. Just right-click on a site's search bar and select Add a Keyword for this Search…. For more detailed shortcuts, set up your bookmark manually with the %s variable in the site's URL. Firefox replaces that variable with whatever you type after the keyword.