I ve already completed my express entry, and have been Invited to apply for PR via CEC.
In the supporting documents checklist, one of the documents required is "Offer of Employment", the information icon says the following
-You must provide a job offer letter from the employer who wants to hire you. It must be printed on company letterhead, and state that you will be employed permanently in Canada by that company. The letter must specify whether the job is:
-for continuous, paid, full-time work (at least 30 hours a week),
-for work that is permanent and not seasonal,
-skill type 0, or skill levels A or B of the 2011 National Occupational Classification (NOC)
(Note – in most cases, the job offer must be for a permanent job. For some types of jobs, it has to be for at least one year.)
The job offer letter must include contact information for the company (address, telephone number and email address).