I have a few film cameras that I do not use very much these days, I switched to a Digital SLR. I have a a few camera bags that I can use for storage. I remove all the batteries from the cameras and put on the proper body caps. The batteries go into a separate plastic box. I put the lens caps on the lenses. I bought a few rechargeable desiccant tins. The desiccant changes color when it can no longer absorb any moisture. Put them in the oven at 300 degrees for a couple of hours and they can be reused. These go in the camera bags with the equipment.
I take out everything out once a year or so and go though attaching the lenses and taking a few blank shots. I check the desiccant at that time as well. The camera bags are all nylon and not completely sealed, the zippers are not waterproof.
I was tempted to put all the stuff in sealed zip lock bags, or wrap the camera bag in a plastic bag. I am not sure if that would be a good idea or not..
I have a few cameras here in humid Florida. I keep the desiccant tin in the bag down here to keep the cameras from getting moldy.