This stability (more than a set temperature) is a key factor in providing a good cellar environment. Wines stored in warmer environments tend to mature too quickly and can spoil easier.
Also make sure that the area is free of odor and vibration and that it is not overly dry. Very dry areas tend to cause the corks to shrink and wine to evaporate. (I find it much more enjoyable to use my body as the vessel from which an evaporation of wine occurs.)
Actually, humidity, in the range of 60 percent to 70 percent, is good for the wine, and you can artificially create this effect by keeping an open container of water around the stored wine.
Obviously, you'll need to store the wine on its side so that the cork stays moist. I will lay screw-cap wines on their sides even though their enclosures don't allow them to improve with age -- it's an aesthetic thing with me. You can also turn case boxes on their sides and use them to store the wine.
While you can age some white wines, most people tend to choose red wines for long-term storage. Wines such as Bordeaux, cabernet sauvignon, pinot noir and zinfandel produced in particularly fine vintage years have the best potential to improve with age.
I've had a wine cellar for years and some of the wines I purchased to start the project are still resting there all dusty and cool in my basement. Every once in a while, I sneak down, stare at them lovingly and, occasionally, bring one up to the dinner table to enjoy with friends and family on a very special occasion.
It's a truly tense situation until you open the bottle because there is always the chance that the wine will be disappointing. But when it hits the mark, you will be thankful for your wine storage area.
For more on the art and craft of wine, visit John Brown's Vines & Vittles blog at thegazz.com.