Nós = we
Nos = us (Você nos deu o vinho./ You gave us the wine)
Nosso = ours/our (Você bebeu nosse vinho./ You drank our wine.)
The subject pronoun "nós" always have an accent. You may be confusing it with the object pronoun "nos". It's similar (with a few exceptions) to we/us in English.
Why does the voice pronounce nh like it was only n? Is h mute in this case, like it was written 'vino'?