I always go by the fact that Agfa kept its uncut rolls at -10C. I understand this to be the best compromise between storage life and energy usage. I always freeze film that I will not be using in a few months.
Relative humity is the amount of water present divided by the maximum amount that air can hold at a given temperature. So a relative humidity of 50% says that the air is holding half the amount it could possibly hold. Warm air can hold more moisture than cold air.
Boxes of paper should be placed in ziplock bags. Film in original containers (cans or sealed packages) can also be bagged but this is not necessary if they are unopened. Whether film or paper has been refrigerated or frozen it should be allowed to come to room temperature before opening the package.