Go check out the HUGE list of papetback books available for only $1 at Scholastic.com!! My daughter is really into books right now, so I may just have to stock up!
If you happen to find a lot books you want to order, you can get 20% off and FREE shipping with purchases over $25 by using the code AFFVDAY (code expires 2/14). The rest of the sale is going on until February 28th.
(This is the correct link, by the way, and I have deleted the old post. Sorry, I couldn't get the previous link to work!)