I don't care whether you use Google Analytics or not. If you do, however, you should bookmark this page: Google Analytics: The Missing Manual.
Then start working your way through it. What a terrific resource (and it's free)!
PS - If you don't have some sort of analytics running on your winery Web site, then shame on you. Google Analytics is free and contains everything you need to improve your Web site (except the will to do it).