You may wish to register for the Australian forum "paging dr". There are multiple threads discussing previous interview questions. People also meet up via skype or in person and actually hold practise interviews specifically aimed at USyd entry. The MMI process is slightly different if you are an international applicant. There are also numerous threads dicussing things like the merits of the Sydney DMD compared to the Melbourne DDS and different costs associated with the degrees and living in these cities. International applicants also share their experiences with the dental application process. Hope this helps!