Rule #1: Keep the Temperature Even
The most important rule of bottle storage is that wine likes to live at a consistent temperature. Storing your wines in a room that's alternately hot and cool (like most people's kitchens) is an invitation for spoilage. Set up some racks in your cellar or a cool cupboard in your home. If you live in a corner of the world with a continental, four-season climate and no central air, you may want to invest in a wine fridge. Whites and reds can be stored together at 55 degrees.
Rule #2: Store Bottles on Their Sides
You may have noticed that wine racks position bottles on their sides -- there's a good reason for this. Wine should be stored on its side so you are constantly keeping the cork moist, which reduces the chance that the cork will dry out and disintegrate into dust. A freestanding or wall mounted rack is a great addition to any wine lover's household!
Rule #3: Avoid Light at All Costs
Exposing your bottles to UV light -- especially sunshine -- can damage what's inside. This is why many winemakers use colored glass bottles; they act as a protector (think sunglasses for wine!). If you're drinking your bottles in the near future, you don't really need to worry about this, but for long-term wine storage, choose a dark location for your wine storage area.
Rule #4: Stock Your Fridge with Some Bubbles
The fridge is one of the best places to store sparkling. You never know when you will have an impromptu reason for celebration -- job promotions, new babies, Saturday! -- or be surprised by guests stopping by I believe that keeping at least one bottle of nice sparkling wine in your refrigerator door at all times is a essential for any great host. You can store sparkling wine in your fridge for quite some time, but be sure to drink it or swap it out every few months.
Rule #5: Take Care of Your Open Bottles
After your bottles are open, you can vacuum-pump them and keep them in the fridge -- it should extend the life for at least a few days and up to a week for some white wines. For the serious collectors out there, spring for a Coravin! It's brand-new technology that allows you to pour a glass of whatever you like without actually pulling the cork. So how does it work? It pierces the cork with a needle, extracts your pour, and replaces the liquid with an inert gas. You can drink that bottle at whatever pace you like, and it will be delicious for months to come.
If you're unable to finish the end of an open bottle for any reason, a great tip is to pour it into ice cube trays and keep these "wine cubes" in your freezer for cooking. That way, when you have a recipe that calls for a little wine, you will always have some on hand without having to open a fresh bottle.