So I am going to go a little Emily Post on all of you. Etiquette is a major factor in all weddings whether formal or casual. Finger food or knife and fork.
Rehearsal
Whether big or small, the organist or musician should always be at the rehearsal as one of the most important details is knowing the time to start the wedding march.
"A perfectly drilled wedding procession, like a military one, should move forward in perfect sep, rising and falling in a block or unit. To secure perfection of detail, the bars of the processional may be counted so that the muisc come to an end at precisely the moment the bride and groom stand side by side at the chancel steps. This is not difficult; it merely takes time and attention"
- Emily Post's Etiquette, The Blue Book of Social Usage
Traditionally it is bad luck for the Bride to take part in her own rehearsal, she is there to watch and to direct. But during the rehearsal she has a "stunt double". This is of course optional.
Processional
Catholic Wedding
The Priest and the Groom enter through the side door and wait at the alter. The groomsmen and bridesmaid walk done the aisle starting with the couple that will stand the furthest away from the Bride and Groom, then ending with the Best Man and the Maid/Matron of Honour. The ring bearer is next and then the flower girl (If included in your party). The Bride and her father/mother/close family relation are the last to walk done the aisle. he bride will walk on the left hand side and is escorted to the alter. If the Father is giving away the bride he will then sit next to the Bride's Mother.
Protestant Wedding
The protestant wedding processional is very similar to that of the catholic. The Priest, Groom and his groomsmen enter through the side door (this is becoming common in all Christian ceremonies). The Mother of the Bride and Groom are seated after all the other guests have arrived. The reminder of the processional is the same as the above.
Jewish Ceremony
For Jewish ceremony the Rabbi or Cantor enters first followed by the Grandparents of the Bride and then the Grandparents of the Groom. Both sets of Grandparents are seated in the first row. The processional then has the Groomsmen walk in pairs followed the the Best Man and then the Groom is escorted by his parents to the Chuppah. Continuing the processional are the Bridesmaids, the Maid/Matron of Honour, Ring bearer/Flower Girl and then of course the Bride escorted by both her parents.
Happy Planning!