Emigrating to America/canada with a profession?

I currently live in the UK, and go to America and Canada every year and love it, I am ex forces, having spent a 3 years in the navy, i have a masters degree in english and now teach english at a secondary school. I have always wanted to move to america/canada, but am unsure of how to get citizenship (specifically america) is it possible for me to get in as a teacher? or as a maritime navigator etc?