Where to put her?
Light, but preferable not in the full light of the sun. However perfectly fit for your window sill.
Water and nutrition
During the growth process of the flower bud you should refrain from watering too often. Once a week in little bits will be sufficient to keep the soil from drying out completely. If Amaryllis gets too much water in this stage, its stems will grow larger and larger until they kink or reach up to your ceiling. After the flowers have opened, you can give some extra water in order to keep the flowers from drooping.
Room temperature is fine. Unlike most other plants, Amaryllis can be kept close to or even just above the radiators of your central heating. It will need a little extra water though!
We are required to inform you that the plant you have bought is intended for decoration, not for consumption.