If you need my advice about grad application to cs@UofT, the following answers the FAQs.

Who decides the admission list? Should I contact profs?
I don't know. There's a grad admission committee, but it may listen to profs' opinion.

Does Prof. XXX hire new students next year?
Again, I have no idea... Sorry...

Which profs work on CV/Graphics?
The group websites provide such info, as well as publications, a great indicator of profs' research interest.

How to improve my chance of getting in?
IMHO, get strong references and publish good works. They convince the committee/profs your potential in the shortest time.

My TOEFL does not meet with the bottomline, should I apply?
Yes. I heard many people get admitted without TOEFL/GRE hitting the bottomline.