People aren't afraid of scrolling, so you can use your vertical space better. You could put the description/call to action closer to the top/center of the page and make them bigger. I would slide the thumbnail images for the books below that. As long as people can tell that there are books there, they'll scroll through them to find one that works.
The set of 50 books on the bookshelf is an overwhelming wall of visual noise. You may want to curate/redact to get fewer books up there (those aren't all what I would consider great kids literature), get rid of the bookshelf metaphor (or at least tone down the contrast). Also, as all of the books are different aspect ratios, there's a lot of extra visual noise in what could otherwise be a tidy grid. Consider cropping them all to square.
Are any of the books available for free? It might help to have one or two free books to get people interested in the concept and to get more feedback/usage data from real humans.
Don't get disheartened. It's a cool concept. I started doing a similar thing for my kid with a digital camera, a mic, and real books but my kid learned how to read before I finished the audio editing.