Every good cook needs a pepper mill or two on hand at all times. These are used for grinding the peppercorns. Freshly ground pepper is so much more pungent than the bottled or tinned variety. Fine grind black pepper from the supermarket starts to lose its potency as soon as the container is opened. In six months time it has hardly any taste at all.
Peppercorns keep well in a tightly sealed container kept in a cool place.
You can't go wrong storing them in the freezer. Green peppercorns need to be refrigerated as soon as they are opened. It's also a lot less expensive to grind your own pepper. I have a spice grinder that I use to grind several tablespoons of peppercorns at a time for the shaker. I only grind what I'll use in a short time.