As mentioned earlier, George R.R. Martin has juts released the newest Winds of Winter excerpt. Now if you couldn't guess, don't click the link if you have not read through A Dance with Dragons. Just to tease you non-book readers though, the title of this chapter is Mercy.
Also if you haven't done so already download the George R.R. Martin's A World of Ice and Fire - A Game of Thrones Guide for another recently released sample chapter.