Cool, dry, dark places are indicated for storage. Note that in this context attics, outhouses, barns, bedrooms, kitchens and basements are not dry places. Rinse well and allow to thoroughly air dry. Carbon steel blades should be cleaned in warm water and baking soda, rinsed well, dried and oiled immediately. Clove oil, magnolia, and camellia are excellent for the preservation of all metalic and many organic materials.
Olive oil is fine for most kitchen knives as it is close to hand and quite servicable.
Kitchen knives should not be allowed to languish at the bottom of a sink full of water and dirty dishes. Surface textures are destroyed in these conditions. Automatic dishwashers are not kind to knives either. The temperatures reached in these machines are too high and run the risk of drawing down the temper of the steel. Also if the handle material is of an organic nature such as wood, bone, ivory, horn, pearl, etc, its life is severly abbreviated by immersion in hot soapy water.