Freshness is very important to the quality of coffee. Ideally, coffee wouldn’t be stored for longer than 7-days after opening your bag of freshly roasted coffee. It is better to purchase smaller quantities of coffee more regularly than to store larger quantities for any length of time.
That having been said, once the bag is open, store the coffee in an air-tight, dark container and in a cool, dry place. Never store coffee in a fridge or freezer, doing so will allow the beans to develop condensation on the surface of the bean, and the moisture will remove the flavour from the coffee bean. Ideally, coffee would be stored in its whole-bean state and ground fresh just moments before brewing.