Congrats to the new guys getting ready to start in august.
I'm one of the 12 that started in melbourne last month so thought I'd throw some advice at you.
You'll receive a USB stick with the ARM + other pre-reading material and study guides. Get through as much of that as you can help... 1 month into the course and the bits of pre-course learning I got through have helped!
Try make sure you get to melbourne/bris as early as possible before the start date to settle in because after a couple of formal induction days you get thrown head first into the theory and you'll want as few distractions as possible.
Course is great so far, expect to be there for 7-8 hours a day, and then be prepared to put another 3-4 hours minimum in a night to get through the wall of theory that comes your way. Obviously anyone who has come from an aviation background has a slight headstart, but it seems like it's levelling out already in our course.
Life changing opportunity so make sure you do everything possible you can to make the most out of it.
I was in your position 3 months ago so if you want to ask any questions go ahead!