Unless you speak Chinese to some extent, you will find it difficult to obtain employment. You may find a local company that is interested in your foreign-language skills and knoweldge of foreign markets. However, local companies will not pay anything like western-based salaries and why should they when experienced, multi-lingual, MBA-graduated Shanghaianese will happily work for lower salary.

There will be some openings in multinational organisations and representative offices, but it is likely that you will hear of these opportunities through networking rather than through formal channels.

Check local career websites such as 51Job and ChinaHR. 

The trick is to be flexible and consider trying positions that you might not have done before. It's great experience and you will be surprised how many doors will open for you.
If you choose to work full-time, you can negotiate a full package, including benefits and working papers.