Don't: Write on the front of a picture
Example: Picture of my Shaw Ancestors
Sure labeling a picture this way makes it easier to identify people, but the integrity of the photo is somewhat compromised. Demonstrate your appreciation of their memories, only write on the back of the original picture. You can make a copy, write in the names, and save it with the original.
Don't: only write the first name, who is Aunt Ann?
This picture alone would be quite a mystery, no mention of whose Aunt this is or a maiden or married surname. Always include the last names, especially the maiden names! Sometimes finding a woman's maiden name can prove to be the most difficult task. You can never assume pictures will stay within a a direct family line, any facts you can include will help tell the story.
Do: Write your name when adding or modifying a label.
Do: Write the date
Do: use Acid Free/Archival Safe Ink
Do: write the location!
I WISH more of my family photographs had some indication of location. Back in the day the family would stick together and live in a relatively local spot, this is probably one of the reasons they didn't jot down the city name or street. With sites like whatwasthere.com and historypin.com you can upload images, mark their location on the a virtual map, and compare the old picture vs the google street view from today. If only we could go back in time and explain this in the late 1800's- wouldn't they be surprised!
Do: ask family members for help!
It's really important to take the time and read over whatever inscriptions you find on family pictures and documents. The smallest detail can be the key to unlocking the secrets of your family. If you have a grandparent or great aunt or uncle nearby you could ask them to take a look at your pictures. This is a time sensitive opportunity- take advantage while you can!
Have fun preserving your pictures!