What do you do on a regular basis while it's not being used?
Cameras are like people - they need exercise! On a regular basis, the shutters should be released and controls and settings should be adjusted.
Cameras with batteries should have the batteries removed if they are not going to be used for a time.
You need to make sure that they are kept in a place with reasonable levels of humidity, at reasonable temperatures.
Cameras and lenses should be checked for fungus growth or infestation (not too likely with an F100).
If a camera is left unused for a very long period of time, a CLA before use would be a good idea.
The camera repair people on APUG can no doubt add even better info.
Matt