Never say "sponsorship" when you are applying for jobs because it implies that the company may have to take some responsibility for you. Instead tell them that you need an offer of employment to facilitate your immigration. Tell them that if they do it, it's not binding for them to actually hire you when they get there in case their situation has changed by then and they have filled the position. If they are still interested, send them to http://www.hrsdc.gc.ca/eng/workplaceskills/foreign_workers/supperimm.shtml and tell them to look at the AEO information there.