I use Australia Post for deliveries world-wide. You may choose the delivery option that is most suitable for you at the check-out. The following is a guide to approximate delivery times (in business days) for various options:
Within Australia
Courier Post (Melbourne metro only): generally same day, possibly next day.
Parcel Post:
Melbourne metro – up to 2 days; Victoria country – 3-4 days.
Sydney/Canberra/Adelaide: 2-3 days.
Brisbane/Tasmania: 3-4 days.
Perth/Darwin: 5-6 days
Other Locations: 3-10 days
Express Post: generally next business day to most capital cities (except Perth and Darwin) and some other major centres.
International
Air Mail: 3-10 days to most locations.
Sea Mail: 8-12 weeks to most locations.