You used to work the company as a controctor last year. They should send a T4 form for you. If you have not received it, you should ask them whether they send it or not. Good luck!
If you worked as an independant contractor (self-employee), no T4 will be sent to you. Instead, you have to fill out form T2032. Also read the following CRA publication: http://www.cra-arc.gc.ca/E/pub/tg/t4002/README.html