I have four plants that I have been growing outdoors approaching harvest time. I have never harvested cannabis before and I was hoping I could get some advice.

1. How important is drying in darkness for THC levels?
2. I understand drying cannabis is smelly when done indoors, but how long will it stick around after the buds are put into jars for curing?
3. How feasible is it to dry in a garage that is not climate-controlled?
4. Does anyone have a recommendation for hygrometers that I can put in the jars? It seems everyone I find on Amazon has poor views when it comes to accuracy and consistency between multiple units.
5. How many half-gallon jars should I expect to need for three autoflowers and one photoperiod?

Thanks in advance