The following is a typical order to a wedding Processional. It can certainly be modified based on your particular situation.
The groom, best man and Officiant enter by using a side door.
They all stand facing the guests.
An usher escorts the grandmother(s)of the bride to their seats.
An usher escorts the grandmother(s)of the groom to their seats.
An usher escorts the mother of the groom to her seat.
An usher escorts the mother of the bride to her seat.
The ushers walk down the aisle (or escort the bridesmaids) and stand next the groom and best man and then face the guests.
The bridesmaids walk down the aisle.
The maid of honor walks down the aisle.
The ring bearer walks down the aisle.
The flower girl walks down the aisle. (Many times the flower girl and ring bearer will walk together)
The father of the bride escorts the bride down aisle.