If you haven't already, take a look at
Baen's store which deals mostly in fantasy and science fiction books. They have a
free library where you can download some of their books for free, and all of their books are also DRM-free. I can recommend
The Deeds of Paksenarrion by Elizabeth Moon.
Sheepfarmer's Daughter, the first book in the series, is available for free in their library.