Canadian SIM card options (in Nova Scotia)?

I am going to be traveling in Canada this summer, and need a Canadian SIM card. In the US, I have been using TMOBILE prepay, and it's quite expensive, imo. Even as a gold rewards costumer, I have to pay 10cents/minute, and 10cents/text message; and that's only in the United States.

When I arrive in Canada, I would like to remove the Tmobile SIM card, and replace it with a local, cost-effective alternative. I will only need to call within Canada. What are my SIM card options in Halifax, NS? That will be my first stop.

And it doesn't need to be prepay again. I can give them the address of my parent's house in Vancouver, and start a monthly billing payment. As long as I get better rates.