This year, our teacher just gave us some photocopies (from that book) relevant to what we were doing. I think she (the teacher) mentioned that all that she found useful were the sections on tone/techniques for language analysis (there's more depth for this stuff, though less organised, around the internet).
Honestly, using material found on ATARNotes (stickies, notes), as well as the copy of the AN study guide and assessment reports, you're pretty much set in terms of finding the requirements of the assessment tasks, and from there, either by yourself, with a teacher or a tutor, you can build upon the foundations these resources give you. The AN book is designed to allow you to further develop your essay writing techniques/strategies, as it gives you the fundamentals of structure, and different approaches.
These holidays, just familiarize yourself with the course, maybe purchase the AN book, read some stickies, and your texts... I don't think there's a need for that book you mentioned OP.