Work Visa application for China

I am a Canadian student studying fulltime in the United States (state of NY). I just accepted a job offer in Shanghai, China for the summer. I know I need to obtain a visa in order to gain entry into China. How and where can I obtain it? Is the only way I can get it is to return to my home province and then apply for one? Or can I obtain one in the United States even though I am a Canadian citizen.
Thank you for your help.