During the cycling of a furnace, how long should it be off and how long should it run? Thanks,

This all depends on the temperature in your house, it goes on when the temp. drops below the set temp. and it will run until the temp. you have it set at is met.

Yep, pretty much,, and also its according to how tight your house is ,the lack of insulation,the windows,how much the doors are fanned open, cold air leaking from around the doors,as to how quick you are losing that wonderful heat that costs us so much

Cycling can also be set in some stats.