Peaceful mind

I need to know how to have a peaceful mind... I desperately need to know how to achieve it. My mum has been going the same temple for last 35 years so. I tagged along with her sometimes and liked that complete silence.. bell sounds.. smells.. and peaceful faces there. She never asked me to pray or anything but told me many stories from books she read. Unfortunately I don't remember stories to tell but somehow I remember this: the Buddha's face reflects your mind at this moment. Since then I always look at the face and I really believe that. Maybe I should follow the monk in the photo to find out how the Buddha shows my mind now.
Photo from http://www.koreanbuddhism.net/data/1/temple/21/200512201135073071.jpg