As a wedding photographer I am probably the person (supplier/vendor) that will spend the most time with the bride on the wedding day, from prep time through to after the ceremony. In this priviledged position I have seen brides that have spent a lot of time detailing the day's timeline after our consultation and I have seen some that decided to just "wing it on the day".
Trust me if I say that the last option is not the good option. This leads to chaos and disaray and adds a ton of stress to the day that should be the most joyous of your life. MC arguing with either bride or groom and looking for support from the one closest to his vision for the day while alienatng the other partner. Guests standing around wondering what comes next and when will it happen. The lsit goes on, in short an unpleasant experience will follow as tensions rise and fill the room.
I want to encourage you to take the time to do proper planning for the flow of events on your wedding day and to consult with your photographer when doing so. It will allow you to plan with your photography in mind so that you have enough time available for shooting each element of the day. Take guidance from your photographer about time required for each item.
Another important item is to draw a list of names of family with whom you want to take group photos as well as designate a person (or two) who knows all the people on the list to assist with gathering them and lining them up in order of groups for each photo. This is not a task that can be managed by the bride or groom on the day, nor does your photographer want to be calling names out into the unknown. Also let each person know before the wedding day that they will be required to pose for a group photo at a designated time. This portion of the photography can very easily turn into a huge time waste if someone crucial wanders off, or worse, the photo never gets taken.
Please head over to my resources page where you can find some useful tools to download which will assist you with your planning process. You are welcome to call anytime for any advice as well, free of charge.