Contents of job offer letter, NAFTA professionals

Hello everyone,

I have a question regarding the contents of the job offer letter needed to show the immigration officer for a temporary work permit. I have been accepted for a position in city government. The position was supposed to begin in October 2011, but due to budget issues, it will not begin until sometime in early spring 2012. The duration of the position is for a year, but now there is no specific end date due to the revised starting date. Will this matter? Can I show the job description which lists that the position is for only 1 year to the immigration officer? What do I need to bring? Please help!

Also, the position is related to urban planning/city management, (urban planners are NAFTA professionals) however the official title of the position is not "urban planner". However, it does show in the job announcement that a degree in urban planning or similar background is one of the key requirements. Will it matter that my position title is not verbatim "urban planner" or will the immigration officer be able to look at these pieces of evidence and put 2 and 2 together?

Thanks so much.