Foreigners wishing to work in Canada must apply for a work permit, either as a skilled worker, a temporary worker or a provincial nominee. In most cases, you will need to submit your application before you arrive in Canada. You have a much shorter wait if you can qualify as a sponsored applicant, or have a job offer that you have obtained from your own efforts or through the provincial nominee program.

Skilled Worker Visas

As of July 1, 2011, you may only apply for a Skilled Worker visa if you qualify for any one of the following categories:

• Several of the 29 recognized work classifications have already reached the maximum number of applications set by the Canadian government; applications that exceed the cap will be returned unprocessed. Cap limits do not apply if you have an offer of arranged employment.
• You must demonstrate proficiency in either English or French. Proficiency in both languages is a definite plus.
• You must provide proof that you have sufficient financial resources to support yourself and any family members who accompany you once you arrive; this requirement is waived if you have a job offer in hand.
• There are no formal age requirements to qualify for a Skilled Worker visa, however, applicants between the ages of 18 and 49 have a significant advantage over younger or older applicants.

Eligible Categories for Skilled Worker Application:

• Holders of Valid Offers of Employment with Canadian Employers
• Ph.D. Students or Recent Ph.D. Graduates of Canadian Universities
• Skilled Workers in One of 29 Work Classifications (Within Specified Caps)

Temporary Worker Visas

In most cases, if you have an offer of temporary employment, you must apply for a temporary worker visa. You may also bring your spouse or common-law partner and your children. Each family member must submit separate applications for temporary visa status. If your spouse or common-law partner wishes to work, he or she must also apply for a work permit.

Your employer must obtain a letter from the Human Resources and Skills Development Canada stating that employing you will not cause an adverse effect on the labor market for eligible Canadians.

See here for the list of documents along with the applicable fee.