Note that you can download various documents on this page, including the Course Syllabus which includes Unit descriptions, outcomes and dot points for each elective in both Year 11 and Year 12.
Note: The dot points seem to have a strong correlation to the essays that have been asked in the last two ATAR examinations. As such, they would be the first place I would look as to likely essay questions in the 2019 ATAR examination.
2016, 2017 and 2018 WACE and ATAR Examinations (ie current course)
These previous examinations should be a mainstay of your ATAR preparation. You should familiarize yourself with the format of the paper, and look for clues as to likely questions.