Apples should be kept cold with some humidity. Store apples separately from other produce.  The produce crispers in your refrigerator are an ideal location.
Apples give off ethylene gas which accelerates the ripening of other produce.  This works to your advantage if you are trying to ripen avocados. However the apples will cause other produce it is in close proximity to go bad quicker.
If an apple becomes bruised, use it quickly as it will go downhill faster than the others. The saying one bad apple spoils the bunch is true. 
Check your apple stash often and rotate the supply whether though snacking or cooking.