About three years ago, Google launched search query data within Google Webmaster Tools.
The reporting in the search queries data is one of the more value areas within Webmaster Tools, especially since Google defaulted SSL search years ago.
Maile Ohye from Google posted a 12 minute video going through all the ways SEOs and webmasters can use the search queries data to benefit their sites and conversions. Here is that video:
I recommend you watch it when you are not distracted. I think for most people, it will be a good 12 minutes spent.
Forum discussion at Google+.