What money do they use and how will I be paid?

The local Chinese currency is called Ren Min Bi or simply RMB. It is often called “Kuai” or more formally Yuan.  There are many banks in China. It is sometimes difficult to arrange to transfer foreign currency out of China.  Your contracts states you will be paid in RMB and be deposited into the Bank of China Account here in China .

Incidentally, you can use your Bank of China card with the “Union Pay” logo on it in any CIBC ATM in Canada  

Chinese tax laws are such that the first 4000RMB are non-taxable. Income tax in China is about 15-20%,  If you are a resident of Canada (have not claimed non-residency) you can deduct the Chinese tax paid from the Canadian tax paid  so the overall amount will not be greater than the total amount of Canadian Tax you would have paid had you received the salary in Canada.