One of the reasons you resolved to start buying wine by the case (see Resolution #2) instead of the bottle is so that you would have an inventory of wine always on hand. Now to the practical part: your little stash of wine has to live somewhere. It's time to establish a cellar.
Let's deal with the semantics first. In this context, cellar simply means a dedicated place where wine can be stored safely for the period of time you are likely to hold it.
Storing wine safely means putting it in a place where it won't be: (a) damaged by extremes or swings of temperature; (b) disturbed by vibration (from a nearby washing machine or dryer, for example) or being frequently shifted around; (c) contaminated by smelly things (paint, paint thinner, pesticides, cleaning fluids); (d) liable to become wet; (e) in proximity to activity that could cause breakage.
In general, you're looking for a quiet, out of the way spot where the temperature tends to be steady, on the cooler side, and with some humidity. In New England, such conditions are often to be found in home basements. Places they are very unlikely to be found anywhere include attics, porches, unheated detached garages, stairways, the nether regions of kitchen cabinets.
As you can see from the photo above, once you have a good spot the actual facilities don't matter much. In this hoary, cobwebbed arrangement it appears the bins were created by pouring concrete into forms. Stacking hard plastic milk totes works; or you could buy something bin-like from Ikea or The Home Depot- so long as the units are really secure in place and not too light duty. You really need bins rather than just shelves, but baskets on shelves work. Alternatively, you make use of an an old refrigerator. If it runs, set it to hold a temperature of 50-55 degrees Fahrenheit.
How serious you need to be about the conditions of storage is really a function of how long you intend to hold the wine. If it's only for a few weeks or months, less than perfect conditions matter much less since the effects of sub-optimal storage only become serious with time. For example, the arrangement I describe here is not suited to laying down expensive bottles for the purpose of maturing or aging them - just for storing more or less everyday wines for a little while before you drink them.
Of course once you get your passive wine cellar established, you'll want some cobwebs, too. You get those here.