Vapor Barrier for inside-out walls

Hi All, I am working on a design for a small studio. The location of the studio is The Hudson Valley in New York, where the average temperature is 50º F. As I understand it the vapor barrier would go on the outside on the inner leaf, against the sheetrock. First of all is this right? Second of all: I was planning on putting the walls up in 8'x8' sections does anyone have suggestions for how to do the barrier? Thanks for everything!