Brotherhood Books is an online secondhand bookstore run by the Brotherhood of St Laurence.
They're currently offering 10% off all books until this Thursday at 3.30pm, to compensate for recent speed issues with the website. The website is still a little bit slow but it's definitely worth a look if you have any particular titles in mind.
These are secondhand books, so they will vary in condition. Check out the Book Condition Guide on the website for an explanation of what constitutes 'fair', 'good' and 'great' condition.
No code/coupon needed, 10% discount automatically applies when you add a book to the shopping cart.
Free shipping if you purchase 3 or more books, shipping for 1 or 2 books is a flat $6.
+1 for brotherhood books. I've bought from them several times and they've been cheap and the descriptions of the book conditions have been accurate. Website is VERY slow though. Another option is betterworldbooks.com who do a similar charity based used book trade with free global shipping.