Work Permit renewal - job offer letter

I am currently on a Working Holiday open work permit that expires Sept. 19th 2011 (aka sooner than I'm comfortable with). I am in process to become a permanent resident via my husband sponsoring me. However, it's extremely unlikely at ths point that my PR will be approved before my WP expires, so I need to get it renewed.

Since I'm American, I actually CAN'T get a Working Holiday WP renewed without spending another semester of study in the US, which I obviously can't do. Therefore I need a new work permit to extend my current job. As we are living in Québec, I have already gotten a CSQ from my PR application - and from what I've read, it looks as though this would exempt me from needing an LMO since I have already been nominated by my province for PR.

LMO aside, what all does my employer need to include in the "job offer letter?" Should he make it appear as if I'm being re-hired on a new contract? For how long should he specify (in reality I'll be working there indefinitely as soon as I get PR)? Should he mention dates like when I was originally hired, etc?

Any help is much appreciated!!