Go to the official Great Southern Railway Web site (see Resources below) and select the 'Indian Pacific' train.
Click on the 'Compare Service Levels' section and identify which class of ticket you want to book. There are two levels, Gold Kangaroo and Red Kangaroo, with different benefits and costs for each. Single adult tickets are moderately expensive.
Go to the 'Bookings' page and schedule your tickets. Use of a travel agent is possible, though unnecessary. If you're having trouble, you can call the sales office within Australia at 13 21 47, or internationally at +61 8 8213 4592.
Explore alternate routes. You could take the Countrylink line from Sydney to Melbourne, and catch the Overland from Melbourne to Adelaide.
Hightail it to Sydney Central Station on Eddy Avenue on the day of your departure. Be sure to arrive at least one hour early.
Bring your glasses or binoculars. You can spot emus, kangaroos and koalas from the train.
Bring some cash and an appetite. Those with Red Kangaroo class tickets can purchase snacks and drinks in the Red Kangaroo lounge car and visit the Red Kangaroo class self-service restaurant car for meals.
Pack a blanket and pillow for the overnight trip if you've purchased a Red Kangaroo Dayniter ticket. These seats recline, but the amentities are limited.