They should all be up on the ANU and Co-op website. I suggest that you only get the current editions of the Legal Citation Guide, the Torts casebook and Laying Down the Law for your first semester. Tradition and Change and the dictionary are both a waste of time.
The Co-op bookstore, the Student Association bookstore and ebay (for second hand books) or online i.e.: www.lawbooks.com.au. I think that Pwaryuex posted some good links somewhere in the general forum.