I have applied for MEng industrial engineering Jan 2016 intake.
Meng and Masc depends on your interests. Generally for MaSc they look for research interests, you must have published journal papers and carried out research beyond academics. If you have journal publications and interested in doing research in a specific domain got for MSc.. The important thing is, you must decide which area/domain you want to work in your future if you have to apply for MSc.. Also for MSc you must get a professor's approval to be your supervisor. For this you have to go the university website and the department faculty page and identify professors who have the same interest as your domain, you have to email them telling about your interests and how you can help their research. If they like your interests they will send an informal acceptance to be you supervisor. You can mention the professor's name in your application when you officially apply.
Meng is straight forward, most universities don't need a supervisor for this. Just apply to the course you like.
Province! for mechanical engg in terms of jobs Toronto, Ottawa, Montreal, Vancouver are the best places to go, they are ever green in terms of jobs. There are lot of companies specially automotive and aerospace here they are like the major cities, getting jobs, internships, part time jobs are relatively easier.
If you want to enter the petroleum and natural gas sector, Alberta is the only place you should go. I would rank Alberta as the number province for mech engineers, but currently there is a major economic crisis happening in the oil sector lots of jobs lost, oil fields shutdown. So currently Alberta is not the right place to be, but keep an eye on it if you are interested in entering oil and gas domain.
Go for Toronto (UoT), Montreal (McGill), Vancouver (UBC), Alberta (UoA) in this preference order.