I was visiting Calgary at the time so it took me 2 days to get my visa but I'm sure if you pay some extra money ( maybe $100 or 200 for multiple entry ) you can get your visa the same day. For the medical report it is just like DOS said but I think you can download a copy of the report from the Chinese consulate's website. I didn't get a medical report before I came here which is ok in some provinces in China because we come from a developed country and the authorities seem to let this slide for us Canadians. You should ask the employer about this!

Take care,
JT