Anyone who uses search on WordPress knows it just awful. Now I have a solution. It's called Swiftype and its very cool. Here is how it works.
You can sign up for free (scroll down and get the free plugin).
Login to your account and get your API Key.
Install the plugin and click one button to index your site.
Then you login to the Swiftype website and you can control what ranks on searches, what should not be included at all, and get great insightsi nto what people are searching for. Its free unless you have a very popular/large website
Check it out at swiftype.com