I am excited and honoured to have my book translated to Chinese. ggplot2 has become far more popular than I ever imagined, and I'm excited that this translation will allow many more people to learn ggplot2. I'm very grateful that Yihui and his team of translators (Nan Xiao, Tao Gao, Yixuan Qiu, Weicheng Zhu, Taiyun Wei and Lanfeng Pan) made this possible.
One of the biggest improvements to ggplot2 since the book was first written is the ggplot2 mailing list. This is a very friendly environment where you can get help with your visualisations, and improve your own knowledge of ggplot2 by helping others solve their problems. I'd strongly encourage you to join the mailing list, even if you think your English is not very good -- we are very friendly people.