The shot list is the list of all the photos you will be expected to produce on your clients’ wedding day, including portraits of individuals and groups. It will determine the equipment you need, the number of assistants—in short, everything required to carry out your assignment, and allow you to keep track of your progress. You should consult with the bride and groom to produce this list. They may well want your opinion on which photos are necessary and which are extraneous. They should also designate an official spotter—someone who not only knows everyone on the list, but can pick them out in a crowd and help corral them for the photos.
Before, during, and after the wedding ceremony, it will be your job to photograph the bride and groom, along with their respective parents, grandparents, best man, groomsmen and bridesmaids, in any number of combinations. There will also probably be a short (or long) list of other people the newlyweds will want to have photographed during the course of the day. You’ll need to be familiar with this list before the day arrives.
You should also make a point of capturing spontaneous moments that occur between guests, which will serve to balance out the formality of the traditional portraits, and more often than not, sometimes these turn out to be the best pictures of the day. Consider bringing an assistant—or more than one, contingent on the size of the guest roster. A sample shot list can be found here.