Create a new world - and you'll start right in a medieval village! Explore the world and find other villages of diffrent types. Buy a house in a village and settle down.
You can add your own houses and village types if you want to.
My cottages mod is highly recommended. Ethereal, RealTest and MineClone2 are supported as well.
The mod places the buildings at mapgen time. That way you'll only find villages in areas on your old map which you havn't explored yet.
Mobs and/or villagers are not included. Add them to your world to make the villages feel more alive!