Airtight is the key...freezing doesn't make much of a difference...plus it make affect the essential oils in the beans.

Get the beans a freshly roasted as possible (check for local roasters in your area or start roasting your own)

Buy only enough for 1-2 weeks use.

Grind the beans just before you intend to brew.

Keep in an airtight, light-proof container, away from heat and moisture (ceramic or steel gasket-sealed canister is great or a canister that lets you vacuum out the air after resealing)

Look on coffeegeek.com for more info...it's the SRP for coffee!