passport name change...

Does anyone know what form i need to change my name on my passport? i know i have to pay b/c i have been married for over a year. And my passport is over a year old.

Also i know i need a certified copy of the marriage certificate. Do i get that from the city hall where i got it originally? Do I have to call in advance or will they give me one if I just show up?
Thanks. i'm so confused. And we want to go away in January!