you write to Mr.and Mrs. John Smith (thats an example you would write the grooms name)
drs.
Dr's. So and so.
It is considered polite to address a wedding card to both people who were married.
When you receive the wedding invitation there should be a small card in a small envelope with the address of the bride or groom's parents name or, in some cases either the bride to be or the groom to be. In the small card you tick off if you are coming and if you are bringing your girlfriend; wife or a guest. The envelope should have a stamp already on it and you just have to mail it out.
Sally and Harry OR Bride and Groom
Since it is the bride's mother who is sending out the invitations, which is customary then the return address should be to your parents or your mother.
the bride and the groom is first, then the bride and her father, and then the groom and his mother. After that the bride dance with her new dad and groom dance with his new mom.
A bride groom is a male. Bride's maids are females.
The opposite gender of groom is bride
Both
bride and groom or horse and groom
there are many ways that you could put this. i agree on bride to groom if they were the only choices. the only reason that i say this is because the brides father has to give the bride away to the groom. so i would say bride to groom but other than if there was maybe another choice it would be bride and groom.