If you do have a receiving line you may want to arrange it as follows:
The bride’s mother, as official hostess, should always be the first person in the line. If the bride has no mother, an aunt or grandmother can serve as hostess. The hostess is then followed by the groom’s father, his mother, the bride’s father, the bride, the groom, the maid of honor and then the bridesmaids and ushers.
It is optional whether or not the fathers or the ushers stand in the reception line. The bridesmaids are also optional. The best man traditionally does not stand in the line.
If there is a long delay between the times the ceremony is over and when the wedding party is able to arrive at the reception site, have someone there to greet the guests and offer them drinks.
The guests can go through the receiving line when you arrive.