While some of my books are limited edition (that means when it sold out, it sold out.  I am not interested in producing any more of it), followings are where you can find some of my books:
Amazon
Smashword
Barns & Nobles
Itunes.
Each book will  also have a page under my site, which will provide you more information about the book, including where to buy it and what language and format are available in the market.