You want your favorite friends and relatives to be at your wedding ceremony (or you wouldn’t have invited them now, would you?). One of the best and sweetest gifts you can give them is good directions. Downloading them from any one of the popular sites is fine, but before you print and send those babies out, test them. Drive the route and see if it is accurate. Nothing is more frustrating, in so many ways, than getting lost. If key guests (or your photographer, etc), are late, not only will they be flustered, but your time conscious vendors and catering staff will be thrown off as well.
Take the time too, to subtly remind your guests that your ceremony is going to start when you have said it will. The rhythm of a wedding is a fragile and lovely thing that does depend on graceful and appropriate timing.