Think of your photographs and snapshots as a living organism. A living organism with a definite and finite lifespan. Photographs are the result of chemical processes and applications and given time, these chemical states are subject to deterioration. Determining how to store and preserve your photographs will ensure that future generations of your family will be able to enjoy their photographic heritage.
Catalog and prioritize your photographic collection. An old photograph, no matter how interesting, means less if you don't know who the picture is of or where it was taken. Record the information about your photographs in a central location or register, and then decide which ones need preservation first. Take into account the condition of the photographs and their sentimental and historical value when prioritizing.
Digitize valuable pictures. Using computer software and a scanner, make digital copies of your most valuable photographs. Choose the very highest resolution possible, and use the .tiff format, not the more compressed .jpg file format. Once you've made digital copies of the photographs, make copies of the files onto a stable medium, like a CD or DVD. Don't trust your hard drive to keep them safe and sound. Hard drives can break, resulting in the loss of your pictures.
Take older photos out of photo albums that have acid-based papers. The acids in the photo album paper can leach into the photo paper and cause deterioration before their time. Take the photos you've removed and place them in albums that are listed as being archival-quality. Do not use glues or any types of adhesives to mount pictures in albums. If you have photos you wish to keep on display, make a copy for display and archive the original.
Store your photos in a stable environment. Locations with wide temperature changes and high humidity can play havoc with the chemicals and paper that make up your photographs. Choose a cool, dry location. If the photographs are especially valuable, consider choosing a commercial climate-controlled storage facility.