Livery yards or livery stables can vary enormously, so you need to consider the kinds of facilities and services you require when looking for a place to stable your horse.
Some yards offer the basics; stabling and grazing, whilst others may provide stabling, indoor and outdoor riding arenas and additional exercise facilities including cross-country courses and gallops. Some may also offer both summer and winter turnout split across several fields.
It's worth thinking about the winter months too and whether they hold events. A livery yard with an indoor or lighted arena will allow you to ride your horse when it's dark outside and a livery yard that holds events all year round will also allow you to keep competing through the winter months.
Your choice will also depend on the type of livery you require. Livery yards may offer full livery - where your horse is looked after for you, part-livery or do-it-yourself (DIY livery) - where you are responsible for all your horse's feeding and care.