A late Smashwords RAEBW freebie I noticed if you still have time to grab it:
Sylvia Engdahl (
ISFDB entry) offers Books #1 & #3 in her self-published YA SF "Flame" series free to download or with coupon. She's also got 50% off a non-fiction book on historical cultural views of astronomy, originally published by Atheneum in 1974.
Also covered in the dedicated RAEBW thread, but I'll mention here that
Gary K. Wolf (
ISFDB entry), author of the books that the cult favourite film
Who Framed Roger Rabbit? are based upon, are offering those for free, along with some Tor and Doubleday backlist books of his, and several others.