Not all old wine is fine wine, and in fact most old wine is not really very good at all.
Even this fact, widely known to wine collectors, doesn't seem to dissuade many people from putting away bottles for those special occasions — which never seem to come. ("This wine is too good for Charlie" or "They'd never understand this wine.")
Yet among wine lovers, setting up a wine "cellar," even one that's in a side room, a garage, or a carport, is one of the most popular of home pastimes.
People are spending loads on fancy cabinets with refrigeration units to keep wines cool; contractors are installing wine racks in closets, and people are digging holes into hillsides to stash wine.
There are also public storage lockers you can rent where wine bottles stay at low, fixed temperatures.
Unless you're planning to stash away 40 cases of wines for the purpose of aging them until they are ready, few people need an elaborate place to store the wine.
As long as the place is relatively cool, has a stable temperature, and is light-free, most wines will be fine for a short period of time, say 1-3 years.
For smaller amounts of wine, putting bottles under the bed or in a usually-closed closet works fine. Racks are optional; you can always get some of those white foam plastic shippers and keep the wines inside, where temperatures are stable.
What sort of wines to buy for such a cache is always a question. Much of it has to do with the person doing the collecting.
If the majority of wines consumed are pinot grigio, muscat or chardonnay, the only reason to have a stash is to avoid having to go to the package store often. Such wines generally do not improve with age.