I do not know how much time is left, but one of the coffee house chronicle's series from Josh McDowell is currently free on Kindle:
Did the Ressurection Happen, Really?
http://www.amazon.co...s=McDowell josh
I read the first two books in the series and really enjoyed them. They are also currently on sale for 1.99 each.
Is the Bible True, Really?
http://www.amazon.co...s=McDowell josh
Who is Jesus, Really?
http://www.amazon.co...ell josh coffee
Blessings,
Peter