The Legal stuff:

The Government is going to want its pound of flesh for letting you get married! The fee for a marriage application is $120
You need to fill in form BDM60 – Notice of Intended Marriage. This is available from any courthouse or the Resister of Births

Deaths and Marriages.
Once you take it in – and one of you must do this personally - it takes three days for them to get it ready for you so make sure you attend to this as soon as possible but bear in mind it is only valid for three months.

If you are under 18, you will need the consents required by law.

If you have previously been in a marriage or civil union you will be required to bring in signed dissolution papers.
On the back of this form there is a list of 64 types of people you are forbidden to marry. So if you’re thinking of marrying your Granddaughter’s civil union partner you will have to think again.

Who can marry you? 
It has to be a marriage celebrant licensed by the government. Most religious clergymen are so registered but today there are an ever increasing number of others who now have the authority to conduct marriages.
If a religious ceremony is desired, an application should be made to a minister, priest or pastor of the bride or bridegroom’s denomination. Most ministers of religion insist on an interview prior to marriage some encourage you to attend pre-marriage counselling course.

Marriage celebrants will travel to your chosen venue and will normally create the service around what you want. It need not have any religious connotations in either words or music. You can choose to add your own order and content of the ceremony. Many write their own vows and choose their own music.

The only part of the service that is legally required is the vows and the signing of the register. Everything else is optional and depend on the couples preferences.

The usual format of a marriage ceremony is:

• A music prelude usually for about 30 minutes before the ceremony starts
• The bride arriving with the person who is giving her away
• An introduction and welcome
• A reading or perhaps a poem
• The vows
• Giving or exchange of rings
• Pronouncing the couple married
• Signing of the legal documents
• A blessing

However there is no need at all to be bound by that format. Just make sure it is tasteful and will not offend any of the oldies!
You will see there’s a list of marriage celebrants in your area on this site. 
You should meet with one of them and see if you can relate well to them. They will undoubtedly have some ideas worth considering and together you should come up with exactly what you require.

One celebrant puts it like this. “A marriage is the wedding of two individuals who surrender to learn to accept each as the other is, in love and compassion. A tip in selecting the person who is going to officiate at your wedding is to select someone you feel a kinship with, someone who has a spirituality you respect. After all, while the ceremony doesn’t have to be of a particular religious persuasion, it should reflect the spiritual bond that the bride and groom feel with each.”