The requirements for real estate agents are different in every state and country. Generally all you need are a few courses and you are ready.
A real estate broker is a person that intermediates between a seller and a buyer of a piece of property or house. He tries to find sellers who want to sell and buyers who want to buy.
Becoming a real estate agent in Ontario is much the same as becoming a real estate agent anywhere else.
There are some classes that you need to take in order to get your real estate licensing. You can find more information on how to become a real estate agent in Ontario by going to one of the local universities and asking them for the career description.
After you finish your college work you probably need to work for one of the commercial real estate agent or a home real estate agency, so you can get real estate agent training. They will be able to help you find your real estate mls listings.
In order to find a broker to train with you might want to look at your local real estate agent directory and call a few of them up.