In the same way that alphabet books introduce the idea that letters are symbols used to create sounds and words, counting books present the concept that numbers are symbols used for counting.  They familiarize the pre-reader with the words and symbols that are associated with numbers and counting, connecting language to numbers in the mind of the young reader. 

Counting books that will get your pre-readers counting:

1, 2, Buckle My Shoe by Anna Grossnickle Hines
Using cloth, thread, and buttons, Hines creates a patchwork version of the classic nursery rhyme.
The Baker’s Dozen: A Counting Book by Dan Andreasen
Follow a cheerful baker through his morning’s work as he makes everything from 1 cream éclair to 12 small cupcakes, after which 13 customers (a baker’s dozen) come in to buy the delicious treats.
Counting Sleepy Sheep by Rory Zuckerman
Explore the numbers 1-10 in this book about a young boy tries counting sheep when he can’t go to sleep.
Ten Flashing Fireflies by Philemon Sturges
Two children catch fireflies, counting through the numbers 1-10 as they add the fireflies to a jar. When the lights of the fireflies begin to fade, the children release them, counting backwards from 10 to 1 as the fireflies escape into the night.
Cool Cats Counting by Sherry Shahan
Spanish numbers and animals are learned while having fun with wildly dancing animals.