If you buy books, there are many places to choose from. Beijing Book Building (formerly known as Xidan Book Building) and Haidian Book Building in Wangfujing Bookstore are both good choices. You can also get a discount if you want to read the original books in foreign languages. Wangfujing Foreign Language Bookstore also has bookstores.
Buying books and reading books are not the same thing ~ uh-huh ~