Not new (been around long time), but in case any SF/F fans overlooked, publisher Baen offers The Baen Free Library -- a digital library of the science fiction and fantasy publishing house Baen Books where e-books can be downloaded free in a number of formats.
Often it's the first book in an ongoing or a backlist series.
(They also have for sale eARCs of brand spanking new books well before available at retailers at http://www.baen.com/baenebooks#eARC )
Links to the download the ones I featured (they offer many more):
- http://www.baen.com/on-basilisk-station.html to download; (#1 of Honor Harrington series) On Basilisk Station - David Weber to see/shelve on booklikes.
- http://www.baen.com/cobra.html download ; Cobra - Timothy Zahn booklikes page
- http://www.baen.com/fledgling.html download; Fledgling booklikes page
- http://www.baen.com/there-will-be-dragons.html download; There Will Be Dragons booklikes page
- http://www.baen.com/caliphate.html download; Caliphate booklikes page
- http://www.baen.com/starliner.html download; Starliner booklikes page
- http://www.baen.com/draw-one-in-the-dark.html# download; Draw One in the Dark booklikes page
- http://www.baen.com/the-honor-of-the-queen.html download; The Honor of the Queen booklikes page