What would a Canadian Citizen need to work in the United States

What would a Canadian Citizen need to work in the United States?
How would a canadian citizen go about obtaining a work permit, resident visa, or green card?
Immigration - 3 Answers
Random Answers, Critics, Comments, Opinions :
1 :
A work permit
2 :
a name change to Perez or Juan .....
3 :
a green card or resident visa.