The government website for studying in Australia: http://studyinaustralia.gov.au
It has multiple languages ranging from English, Portuguese, Bahasa Indonesian to Chinese and Vietnamese. It provides general information about the lifestyle, education system, English courses, scholarships and estimated living expenses in Australia.
This is an Australian site of a global website called International Student http://australia.internationalstudent.com/ . Apart from offering general guide for students to study abroad around the globe, it advertises some products and services to students such as phone cards, insurance and travelling.
National Union of Students (NUS): http://www.unistudent.com.au/site/ This site is built for the benefits of students of many kinds: women students, indigenous students, international students, queer students, postgraduate students. You can get support from NUS on legal advice, sports associations, campus bar, etc..
http://www.studiesinaustralia.com/. This website gives details about secondary and tertiary education, and course searches in Australia. It also provides some guidelines about accommodation costs, living expenses and study costs.
Overseas Student Health Cover (OSHC)
OSHC Worldcare, but not as popular as Medibank.
Visa
The immigration site about different student visa options: http://www.immi.gov.au/students/