Are you selling from the site? If not, I'd argue that you want something very much like a landing page; and what sort will depend on your audience.
Regardless of audience, you want one exit route - so every link goes to Amazon (or wherever you're selling it). If it's technical, I'd probably go slightly longer form (although still one page) - explaining the chapters, explaining the content, etc. etc. If it's fiction, probably a very quick overview as I'd guess the conversion is slightly easier and you're just looking to get them to Amazon to buy the thing. A friend of mine has this for his recent fiction book(s): http://jamiehumm.com/ - page reflects the cover, short synopsis, everything links out to the book.
If you're not set on Wordpress, look for some of the landing page generators - you can probably achieve the same thing with less work.
I'd start by figuring out what makes a good "book showcase" that converts well.
Does it need a preview of the first pages ?
What kind of layout is popular ?
What information should you give your potential customer ?
Make a list of the key features you need, you can use Amazon and any service that does what you need and does it well as a source of inspiration.
Once you have this it's merely a question of finding the appropriate theme that fits your needs. I used Themeforest when I still developed on Wordpress.