Verso books has a half price sale on e-books and paperbacks. I’ve grabbed Genes, cells and brains, which I probably had wishlisted even before I noticed the Margaret Atwood recommendation. Verso has an interesting non-fiction catalogue, worth looking at if you’re thus inclined.
Also, there’s a lovely Humble Bookperk Bundle available right now. It includes a whole bunch of HarperCollins titles, including authors like Neil Gaiman and Lois McMaster Bujold. I haven’t bought it yet, because I happen to already own the most interesting handful of them, but I hope they’ll add an extra to win me over, because I really like buying humble bundles. (Charity and stuff. And buying bundles means making sure there’ll be future bundles, and I really like bundles. So much, I’m going to type the word bundles one more time.)