While my focus on the day is on documenting your wedding in a natural way, I understand that you may want a few group shots of your close family and friends and I am more than happy to take these for you.
I have a way of doing group shots that means we can get through 6-7 shots in around 15 minutes.
I recommend keeping these simple. Groomsmen, Bridesmaids, Brides family and Grooms family are the key 4, plus one with your children if you have any. Every family is different though and you may have step family or a close group of friends to add in. I highly recommended keeping the number of shots down to the minimum as the more you add in the longer you will have to stand around waiting for people to get into place and this time is eating into the drinks reception. I don't recommend shots of "all the girls or "all the boys" as these take ages to organise and I think I would get better shots of these guests naturally in that time.
I will take these about 10-20 minutes after you ceremony ends, usually at your church or registry office if you aren't at one venue all day. Guests are easier to grab at this point before they get anywhere near a bar! I like to get on with them so that they are over so and you can both spend the rest of your day relaxing with guests.
If you would like a large group shot of every guest and you have over 50 guests I suggest only doing this when I have a high vantage point to use, such as a first floor window. Some venues will have a spot like this which is regularly used, but not all do. Please check with them. If I can't get up high then too many faces are buried behind the front row and the image is a bit of a mess and my time is better served capturing people naturally for you.