Why storage is so important
Freshly roasted coffee beans will "de-gas" (release carbon dioxide) for several weeks after having been roasted - but the majority of the degassing will occur within the first 3 days. As time goes by, it becomes easier for oxygen to enter the bean. As such, it's important to keep your beans out of the elements. Keep freshly roasted coffee in a cool, dark, and oxygen free environment.
What about green coffee bean storage?
If you can't store your green coffee beans in a nitrogen-sealed environment, don't worry. They will keep just fine in a breathable bag left in a cool, dry place.