Prior to your Marriage Ceremony you will need to complete a Notice of Intention to Marry. See link below to download NOIM.
Your Celebrant needs to receive the form no earlier than eighteen months before your marriage date and no later than one month and one day before your marriage date.
Your celebrant will also require the following documents for both parties;
See link below to Dept. Births Deaths and Marriages
Your original Birth Certificates
If you are from overseas, your passport
If you have been previously married or widowed, your Divorcepapers or Death Certificate