This is purely a personal point of view--I think truffle oil is a huge waste of money. Sure it seems like a much cheaper way to try and infuse truffle flavor to your cooking but it does not compare to real truffle shavings. Restaurants typically use truffle oil to make a dish sound more expensive and increase the markup accordingly.

If you absolutely must have it in your pantry, it should be used as a finish (i.e., drizzled/mixed into your dish after cooking is done otherwise all the flavor/aromatic compounds of the truffle oil will disappear and you'll likely have plain olive oil). If you don't use it fast enough all monounsaturated or polyunsaturated oils should be refrigerated but fats are notorious for picking up odors. Keep in an airtight bottle if you choose to refrigerate.