When developing a website to promote your book, you have two primary choices. You can launch a site for the book (booktitle.com) or for you as the author (authorname.com). This question comes up a lot and in the world of nonfiction books, my recommendation is almost always to develop an author website instead of a book site.
If the goal is to brand you as an authority in your field, professional speaker, media interview source, and to tie it in with your business, it makes more sense to focus efforts on developing your personal brand, with your book being an extension of that brand. Maintaining a primary author site also makes it easier to manage if you intend to write additional books in the future.
Of course you can still have a separate book site if you really want to, and some authors prefer this strategy. However, I would personally rather focus my efforts on updating and promoting one primary site and driving all of the traffic to that specific site.
Another consideration is that a static book site that doesn’t change often isn’t going to help you much with Google. Google wants to see fresh content, so no matter what kind of site you launch, make sure it includes a blog that you update often.
I’d love to hear how you’re managing your website presence and promotion for your books. Please share in the comments below!