This video on ammunition storage came out several years ago. Extremely logical in their recommendation for using military ammo cans for ammunition storage as well as detailed labeling. After watching when it first came out I changed my practices and now store ammunition in a similar manner.
While true US military ammo cans are harder to find there are several clones out there that will work well. Wal-Mart and Academy Sports carry reproductions that I have purchased for $12-$15. I recommend staying away from the Blackhawk brand as the samples I have seen had horrible welding.
A few things mentioned in the video:
Keep your powder dry!!