If your bottles are stoppered with natural cork then you should store them sideways.If they are closed with screwcaps or synthetic ‘corks’ instead, they can be stored either on their side or upright.

Champagne bottles though should be stored upright.
Store for an appropriate amount of time, which means that most red wines mature in 2-10 years, while the white ones should be consumed after 2-3 years of storage.

The ideal temperature for wine storage is somewhere between 10°C and 14°C (50°F to 58°F). This can affect how quickly a wine matures.
Avoid choosing a place for storage where the temperature is not constant and stable during the day, unless its fluctuation is said to be about 2 to 3°C (5°F) but only a few times per year.

The right conditions are vital so you should store your wines in a dark, stable place with natural ventilation in order to keep just a little humidity that can help the cork. Light, vibrations and mold can destroy the wine in a short time. As the wine breathes, it can be tainted through the cork if stored with anything that has a strong smell. So make sure you keep it isolated.