Newbie Looking for Advice on Incubating My First Eggs

The chicken bug has definitely been caught here at my house (and no, I don't mean bird flu)

I am really wanting to try incubating some of my eggs so I have been doing tons of studying about how to build an incubator (I am pretty handy with DIY projects)

I have most of the parts around the house already so I will be posting my cooler incubator and testing it before I try to introduce any eggs into it. I have a cool idea for a turner and a good grasp of what to do to keep the temp and humidity to certain levels. I have a few questions remaining though:

1) When collecting the eggs to put into the Bator, do I just keep them at room temperature or do they need something cooler like a cellar? Also, it is getting cold here in Michigan... Do I need to get the hatching eggs out of the coop before they get too cold? Basically if someone could just give me a rundown on what to do with this I would greatly appreciate it. I can collect all the eggs needed in 2 days because my 5 hens lay 3-5 eggs a day and I want to try incubating 6 eggs for the first try.

2) What is the correct humidity or humidity range for the eggs during the incubation period. There seemed to be some disagreement about this in some of the threads I read. Do I keep them at a constant humidity or do I change the humidity once they are ready to hatch?

I think I understand everything else, but if there are any common newbie mistakes I should avoid please feel free to share them. I have 4 kids who will be anxiously awaiting the chicks so I would like things to go well if possible.

Thanks in advance for any help you can give!

Edit: Forgot to mention, I have read on here how to make sure they are fertilized and they are indeed fertile. The ring is quite apparent.