Store it in your stomach of course!
Seriously, there are varied viewpoints to how air and exposure to the "elements" affects the whisky.
Basically, I follow these guidlines:
No extremes of temperature
No direct sulight
When available, I always keep my malts in their original box/carton
Of you follow that, you will get a long time out of your malts. Malts change, people change, you may notice a difference, you may not. Some suggest wine vacuums or other devices. That's fine too. However you get your enjoyment is crucial.