I'm finding an extension that allow my customers to preview the books.
Sorry because my english is not good!
Try googleing for "magento flip book". I did and I found these:
Check Booking System Pro, look amazing with cheap price bookingsystempro.com
I'm not sure what you mean exactly but here are some suggestions for you.
You can ahve a look at this Flipping Book extension: https://amasty.com/magento-html5-flipping-book.html
Or Quick View extension - https://amasty.com/magento-quick-view.html