Wrap with furniture pads to protect from soil and scratches. Wrap the legs together with packing paper and, if possible, tape them to the protective wrap placed around the corresponding item. Photos -old photographs tend to curl over time. To keep them flat, place them between two pieces of cardboard and tape them together. Do not store irreplaceable photos.
Negatives take up little space.
Consider keeping them with you. Leave a few inches of space between your items and the wall for better ventilation. Use wooden pallets to stack your boxes on in your unit for ventilation underneath your goods. Gather the things you are least likely to need during the time you are storing your belongings. Place these things in the room first.