In light of my post about preaching from a tablet, here are some Kindle books that may be worth looking into. The price can't be beat: all of these books are being offered for FREE (at least for a limited time).
Heaven for Kids by Randy Alcorn
Erasing Hell: What God Said about Eternity, and the Things We've Made Up by Francis Chan
Crazy Love: Overwhelmed by a Relentless God by Francis Chan
Forgotten God: Reversing Our Tragic Neglect of the Holy Spirit by Francis Chan
And, for those of you who haven't gotten your Kindle yet, you may want to think about picking one up. It is a great ministry tool and good item to have in general (at least in my opinion).
(HT to Tim Challies for the book list.)