Unless you have a specially designed wine cooler, you'll need some sort of rack system to hold your wines in your wine storage area because wine is best stored lying on its side. Fortunately, just about every type of rack system is (more or less) equally good in terms of how well it protects your wines. So long as you ensure that your wine racks are stable, the choice of racks will be determined by quality, convenience, price, and aesthetics.
Start Small with Wine Racks
Although there is a wide selection of large wine racks designed to go against walls like a bookshelf, you are probably better off if you start with smaller shelf-style wine racks. These smaller models accommodate between 12 and 18 bottles of wine and can be placed in a closet, on a shelf, or wherever the conditions are best for wine. Unless you have the time and money to dive into the deep-end of the wine world, this is where you should start because it will be more than enough for casual wine drinkers.
If you start to collect more and more wine, you'll need to plan ahead for a larger wine rack. One thing to keep in mind is to always buy a larger wine rack than you currently need because you are sure to fill up the extra space sooner or later. You should also buy more racking space before you need it, thus ensuring that you always have a place to properly store your wine.
Individual vs. Group Storage Racks
Some wine racks are based around cubby holes which hold individual bottles while other wine racks are based around large diamond-shaped boxes which hold several bottles at once. Wine racks with cubby holes have the advantage of making it easier to examine each bottle and create an air buffer around the bottle to ensure circulation and consistent conditions.
On the downside, wine racks with cubby holes require far more space per bottle and often can't accommodate large, over-sized bottles. Wine racks based around large boxes are a much more efficient use of space, allowing you to store more bottles at once as well as larger bottles. This is a popular choice among the most serious collectors because they have the greatest need for the most space.
Wine Crates as Wine Racks
Some wine experts will use the original wooden wine crates to store their wine. Obviously the wine crates are perfectly suited for the wine shipped in them and manage to preserve a dark environment with fairly consistent temperature and humidity conditions.
Using wine crates as wine racks work well if you're going to keep the wine cellared for a long period of time, but it's far less convenient if you want to check on them or remove any particular bottle. You also can't stack them because they aren't designed to bear weight while on their sides, so this is not a system which permits a large collection. You certainly shouldn't use cardboard boxes for this purpose because it not only absorbs chemicals, but also moisture leading to mold.
Metal Wine Racks vs. Wooden Wine Racks
The most popular materials for wine racks are metal and wood. For wine racks that require extra strength, metal will usually be the only option available. It's also possible to shape metal in a wide variety of aesthetically pleasing shapes, creating something that is both a piece of art as well as a storage solution for wine. If you choose to use metal, you should either use unpainted wrought iron or ensure that the metal is painted well enough that it won't quickly start chipping away.
Metal wine racks do have one significant drawback: metal conducts heat much more efficiently than wood. Because heat can be an enemy of wine, this temperature conductivity could become a problem. It won't damage wines that are stored for a short period of time, but people who cellar wines for several years prefer to use wood because of the better protection it offers. There is also the fact that if you accidentally knock a bottle against the rack, it's more likely to shatter against a metal wine rack than against a wooden wine rack.
Wood, however, is not as durable as metal. The more humid conditions which are best for wine can promote degradation and rot in wood. This means that the wine racks themselves must be monitored as well. You'll get more life out of wooden wine racks if you use a harder, more durable wood like mahogany — though that is also more expensive than oak or pine.