You need a full time job offer from your employer and your employer needs to obtain an approved LMIA. Once you have the full time job offer and approved LMIA, you can then apply for a work permit.
The employer has to pay a $1,000 fee. They also have to advertise the job for a month to prove no Canadian could be found for the role. The processing time for an LMIA could be as long as 4 months.