There is a two-step process required to obtain a work permit.

The employer part:

The first step is for you as an employer to apply to the Temporary Foreign Worker Program of the Employment and Social Development of Canada ("ESDC") for a “labour market impact assessment” or “LMIA”. An LMIA confirms that there is no Canadian citizen or permanent resident who can do the job for which you are seeking to hire the foreign worker.As the employer, you will be required to provide evidence that you have searched for, and been unsuccessful in finding, a Canadian citizen or permanent resident to fill the position. LMIAs are overseen by Employment and Social Development Canada (ESDC) and have an associated application fee of $1,000 for each temporary foreign worker position applied for.

The LMIA process is different depending on whether the targeted employee is classified as “high-wage” or “low-wage”. Temporary foreign workers being paid under the provincial/territorial median wage are considered low-wage, while those being paid at or above are considered high-wage. Depending on whether a prospective employee is classified as high-wage or low-wage, certain specific provisions apply.

The employee part:

Once the LMIA is obtained from Service Canada, the employee can make an application for a work permit to the Canadian Consulate or Embassy abroad that is responsible for his or her country of residence or country of nationality. In the case of an employee from a country whose citizens do not require a visitor visa to enter Canada, such as the US, Australian or Western European countries, the employee can obtain his or her work permit at the border or airport once an LMIA has been obtained. 

After a positive LMIA is issued, a temporary foreign worker has six months to use the LMIA to apply for a work permit. No extensions will be given. If the six-month period expires and the foreign worker does not submit a work permit application, a new LMIA application is required.