Hi Sam,
Its a good effort but my 2c..
One of the basic rules of advertising:
Dont push you you you but what you can DO for THEM. Readers immediately want to know what's available from this site that they want. What can it/you do for them?
To be hit smack in the face with a huge BUY NOW button, puts me right off. AFTER Ive read about the product or service, THEN I will decide if I want to buy, dont push it in their faces.
Design-wise, too many typefaces, styles, weights and colours, try and make the text styles a little more complimentary in each section.
Id go for the more professional look over the hard sell, personally.
Maybe some samples of your work? Even if its some scattered newspaper clips with your name as the author? Testimonials are great, keep them.
So basically, put the BUY NOW button down low on the page, smaller would work also, and I'd replace your header image with newspaper cuttings possibly with website name, not the e-book name.
Give the book its own "space", as more than likely there will be more e-books
All the best, nice work.