These decisions are the last minute details that a bride struggles with right before the wedding. The good news is, you can do whatever the heck you want. Listing someone’s name in the program is a nice way to give recognition to someone that has helped you.
It sounds like you’re adding people’s names in the program like the example below. If that’s the case, on the left you can put the “schedule of events” on the left with the names, and on the right you can include people that don’t have a speaking role in the ceremony. So on the right, it all depends on how much space you have to include people. After you’ve included the important folks ( family, the wedding party, etc), then I would see if you can include folks like the guestbook attendant.
If the wedding singer’s name is already on the left, it’s not necessary to list them again on the right. The wedding coordinator is a vendor so I wouldn’t list them. However, if the coordinator was a friend that was helping you out of the goodness of her heart, I would definitely list her. I would add the guestbook attendants. Reception vendors I would definitely exclude since the ceremony program is just for the ceremony.
Another approach I’ve seen, is to list simply the order of events on the front with no names, and all the names on the back including the relationship to the bride/groom. Here’s an example I found:
I hope that helps!