Once you have your family photo collection in hand, here are some preservation instructions:
1] Identify each person in the photo & the approximate date of the photo. [Exact date is preferable.] You will probably need assistance from other family members.
2] Store the pictures in acid free photo sleeves. Place them in an album or file box by family, person, date, whatever works best.
3] You may also want to scan the photos into your computer or copy them to a disc.
Always be ready for surprises. About 10 years after I got started researching, one of my cousins sent a series of e-mails with family photos asking if I could identify when they were taken or who were some of the people photographed.
The only pics of my paternal grandmother that I had seen were after I was born, when she was in her late 60s & early 70s. As my grandfather died in 1939, I had never seen a picture of him. These pictures dated from about 1911 to the late 1930s. My grandparents' wedding picture, a photo of my grandparents and grandpa's sister & brother-in-law, my great-grandmother and a four generation photo were among the gems.
Using my Pop & family records as resources, I was able to ID & approximate the date on all of the photos. The only mystery remaining is whether the infant in the 4 generation pic is my father or aunt. [Generic wardrobe for infants back then!]