A job offer letter is a document that a Canadian employer gives you (as a temporary worker). It explains the details of your job.Canada job offer letter checklist. Position (job title), job description, start date, and probationary period. Search 40 Fairfax jobs now available on Indeed. Com, the world's largest job site. Any job offer needs to be validated through LMIA, or else they are not considered, no matter what your employer says. Start with a strong opening that captures attention and clearly states the position you're applying for. The following information will assist you in applying for jobs with Fairfax County. You may also download this helpful brochure to assist you.