Visit the locations
When you've got a good idea what shots they want, arrange to meet the couple at the church or other venue where the wedding will be taking place, ideally at about the same time of day as the ceremony. Take your camera along and take test shots, paying attention to the direction of the sunlight. Ask the couple to stand at the altar so you can find a good vantage point to photograph the ceremony without disturbing the proceedings. Find a good location for the outdoor group shots; this is usually outside the church door, for two very good reasons. First, most churches have the main door at the west end, so it will be the best lit area in the early afternoon. Second, there are often some steps, which makes it easier to arrange people of different heights. However if there isn't room, or if the light is blocked by a nearby building or a tree you'll need to find another good location, preferably with a nice but not too distracting background. You should also find a nice spot to take the traditional post-wedding romantic photos of the bride and groom. This should be a different location to the main group shots.
This is also a good opportunity to introduce yourself and speak to the priest or official who will be conducting the ceremony. Ask if there are any particular restrictions on photography during the ceremony, or on the use of flash in the church. As long as you're polite and professional you'll usually find the priest to be a very helpful contact, since he does this every week and knows the building well.
Also try to visit the place where they're having the reception, and scout that out as well. Look for good vantage points, and if you're also a guest at the feast, see if there's a secure place where you can store your gear after you're finished shooting. It's difficult to relax and let your hair down if you're worried about your camera kit getting damaged.
Get some help
You're probably beginning to realise the amount of work you're going to have to do on the day, so be sensible and get some help. Ask the couple if there's anyone in the wedding party that can act as "casting director", to make sure that the different groups of people who will be appearing in each shot are ready, and that nobody leaves for the reception early when they're needed for a shot. Ideally it should be someone who knows most of the people who will be there. The groom's father may be feeling like a bit of a spare part on the big day, so helping organise the photos will give him something to do.
It's also a good idea to get some help with actually taking the photos. Just having someone to hold a reflector for you, keep hold of your spare batteries and memory cards or pass you a different lens can help keep your stress levels down and keep you concentrating on the job in hand. Professional photographers can afford to hire an assistant, but if you're shooting for friends then chances are you'll be able to find someone who won't mind giving you a hand.
Next week I'll continue with some tips for the big day, including suggestions for shots to try, but in the meantime I'll leave you with a list of suggested shots, which you'll find on the next page. These are just guidelines to get you and the couple thinking; feel free to add your own ideas and of course any requests from the couple.