Many countries require you to pass a test to gain citizenship, and Australia is no exception to the rule. The Australian citizenship test comes at the end of a long process ranging from interviews to securing a visa to traveling to Australia. The interview is typically required even if you don't have to take the citizenship test, such as when an applicant is over 60 or under 18.
Preparing for Australia's citizenship exam involves far more than reading a book or paying for the citizenship application. (That fee covers the exam if you take it.) For example, the citizenship test for Australia assesses your English language skills. If you aren't at least somewhat fluent, you won't pass. Don't worry. Failing the test won't jeopardize your residency.
Suppose you've learned English. What else can you do to prepare for the citizenship test? We'll assume you have your original documents and can prove your identity. These documents must be brought to the interview. Test applicants must prove they are eligible to sit for the Australian citizenship test. Those born to former Australian citizens who lost their citizenship upon adulthood or were stateless but born in Australia typically don't have to take the test. If you have a significant visual or hearing impairment, you won't have to take the citizenship test. However, most applicants between 18 and 60 do.
The test is intended to demonstrate that you know the basics of Australia. It quizzes you on the rights and responsibilities that come with citizenship. You should take practice tests to reinforce what you've learned and shown you what you need to study further. There are plenty of free simulation citizenship tests available online that feel like you're taking the real thing. Taking these online tests has the side benefit of reducing testing anxiety. After all, you'll have had practice answering test questions online.
This infographic by Citizenship Australian provides a few more tips for those getting ready for the Australian citizenship test.