I came into Canada March 2010 with a youth program - open work permit. It expires March 2011 and I would like to extend my stay in Canada. I am debating whether to apply directly for my PR sponsored by my Canadian common law partner or first try to extend my work permit with an employer specific position (if given the possibility).
I would like to continue working during my time here, and didn't know how long it is before I can work wihile the PR application is being processed.

Also, I was a little confused after reading some of the forum posts... some say that I continue working after my open work permit expires while I'm waiting for the response? If this correct?

Under implied status, you are permitted to continue working while an inland extension of a work permit is processing. However, youth program visas are not generally eligible for extension, so refusal of such a request may be expected (unless you seek change of terms, which may require a Labour Market Opinion). Although an open work permit may be issued following approval-in-principle of an inland spousal sponsorship, the timing of such will likely mean that you will end up out of status if your work permit expires and are not granted extension.