How should I store chocolate the best?

Chocolate is best stored in a dark, dry and cool place.
For pralines that is below 18 °C. During the summer you may even keep them in the fridge provided the chocolates are sealed from the air. Before you eat them let the chocolates come back to room temperature.
Bars are less sensitive, the maximum temperature is about 22 °C. During the summer you do the same as with the chocolates.
For filled bars subject to the same rule as for the chocolates.