We love this plant! It is one that we suggest to the first time houseplant buyer. It tells you when it needs a drink and if it is happy it sends out beautiful new leaves and the odd flower at a rate of knots.
Bright indirect light.
Give your Peace Lily a really good water and then let dry out. A tell tale sign of overwatering is a discolouration of the leaves. As mentioned above, it doesn't hurt every now and then to let it flop a little before you water it.