I rarely get to see the Australian Ballet these days (moved to Brisbane and they rarely tour here and I haven't spent much time in Syd/Melb in recent years) but the tiny Amber Scott is really lovely, you should see her if you can. However, Aus ballet website says casting is only available one hour before show, so chance of getting a good ticket is unfortunately greatly diminished if you have to wait until then!
Unfortunately I have no idea on the bookstores- I've bought nearly all of my ballet books overseas. Hope you find something, and have a wonderful time in Sydney