A consistent storage temperature is the most important thing to remember. A slight change of ten degrees is acceptable but large, constant fluctuations can damage your wine. Storage temperature should range between 45-55 F (7-13C). Avoid appliances, sunny windows and garages for storage areas.
Keep your bottles upright for a few days after bottling to allow the corks to expand. Then store your bottles on their side to stop the corks from drying out (thus preventing too much air from entering the bottle).
Avoid excessive vibration in your storage area (i.e. under a set of heavily used stairs or near machinery) which can spoil wine through oxidation. Also avoid chemicals and paints.