It's slightly late, but for today and tomorrow, on Tor.com, you can download the first book in the Stormlight Archive, The Way of Kings, for free. You have to download it between 12:00 AM ET, March 23rd and 11:59 PM ET, March 24th, 2017. This is a crazy great deal, though, so if you don't have an ebook of this, do this right now!
It's really easy, too. All you need to do is put in an email address, then Tor sends you a link where you can download the book. You can download it in .mobi (Kindle format) or .epub (other format), and it seems to me these are DRM free. So that's awesome. It could not be easier.
Unfortunately, this is only for US or Canada. I suspect it is because Tor is only in charge of publishing rights in those regions, whereas other publishers are in charge of other countries. But, if you are in US or Canada and you don't have DRM free ebooks of this, I'd download this right now.
Go to http://giveaway.tor.com/ to get your link!