Of course, there are all the traditional routes for finding vendors - the bridal magazines and websites and referrals of friends. Unfortunately, all of my friends that are getting married/have recently gotten married chose completely different locations from those I'm considering, and i can't help but believe that there are some gems that aren't listed in the advertising directories. But I do trust recommendations!
Totally gratuitous picture of Barboursville
While I am obviously not working with any vendors yet, I am perusing websites and such, and I was surprised to find that some of them are incredibly helpful! The Barboursville Winery has a handy-dandy list of recommended vendors on their website, as does Festive Fare Party Rentals (and theirs provides complete contact info on each vendor). How freaking nice of them! I love when people put lists together for me. Now, if only there was a way to convince all vendors/venues/etc. to give a handy-dandy price list on their websites!