Vapor Barrier for inside-out walls

[CyborgAudio]

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!