You never know where you will find an interesting book. There are a few large well-organized bookstores but don't neglect the book corners of supermarkets. Some of the books from the Shanghai and Guangdong publishers don't make it to Beijing so stay alert during your travels. Online ordering is usually not as convenient as in the United States. This is beginning to change as you can see below.
People do buy books and CDs they find on websites but they remit the money through the post office.
Chinese, Altavista Chinese or another Chinese language search engine by using the search term bookstore Online Bookstores All Sages Bookstore several hundred meters northeast of Beijing University. An excellent selection of academic books especially in the social sciences. Most of their business is by mail order. Started by Chinese students in the USA in 1997. Com Modern Books BooksChina .