From the time we're children, we're told stories about poignant, family possessions that will be ours one day. These heirlooms can be of great financial value, like jewelry or a coin collection. But often, heirlooms are passed on because of their sentimental value. To their owners, they're priceless. If you're the lucky recipient of such a family heirloom, here are some tips for preserving its history.