I
just did this a few weeks ago with strawberries I had frozen from
last year!
It turned out GREAT.
I used 'Certo' pectin, you should be able to buy it in Montreal. I just followed the instructions for strawberry jam that was in the box with the Certo. The strawberries were fully thawed and I didn't do anything different than the instructions for fresh berries. Like I said, it didn't turn out any different. There is no need to put sugar on the berries before freezing.
Good luck!! :D