Dolly Parton started a program to give a book each month to preschoolers to foster literacy. Through local sponsors it is now offered in various places across the country. It is a free book geared to the age of your child, no strings attached. My son is signed up and he has gotten some great books! I believe the children receive a book a month until the age of five.
Click on "First Time Visitor" and then "I would like to enroll my child" to see if it is offered in your area!