Get your marriage processed quickly!
It can take 10-14 weeks for your licence to be processed and the certificate to be issued when you order it. However, these steps may expedite the process and shorten processing times to 2-6 weeks.
Before you meet with the Marrying Lady:
Get your licence from City Hall (application for the licence here)
Apply for your marriage certificate online here. Yes, that's right, apply for your marriage certificate on the morning that you are getting married/having your paperwork completed (it won't work earlier). You will get the order number on the receipt at the end (if you don't go back and make sure you've requested to 'submit online' and not 'by mail'). Take note of the order number for your letter.
The $15 Certificate is accepted for Immigration to Canada. The $22 Long Form is sometimes required when moving from Canada to other countries.
Write a letter stating your urgency for expediting your marriage licence in order to receive your certificate. A sample letter is on my blog here. In that letter, state your Licence Number (starts with a G and is at the top of your licence in red ink) and the order number from your receipt when you applied online. Print this letter out and bring with you, or email it and bring $3 to have it printed.
Scan/print copies of any documents which support your urgency (if any): passports, visas, airline tickets, wedding invitations, employment letters
Get an Expresspost envelope from Canada Post. (Not a Priority envelope, as all mail goes to a postal box) or leave me $20 and I'll pick it up for you.