Welcome Ksp925!!!
I couldn't tear myself away from BYC last year when I just started hatching, you will find it very informative, which is comforting when trying something new.
I personally can't stand the idea of an egg going rotten and bursting in my house,
so I candle and remove duds ASAP. I find silkie and cochin eggs to be easy to candle, the color is not hard to see through. If you are on day 5 or 6, and you can see the yellow of the yolk, but no veins, then the egg is what we call clear, if it hasn't developed by now it never will. If the egg has a porous shell and it is difficult to see through, I leave it a little longer and recheck it a few days later. If by day 10 you can't see any development, I toss the egg. Here is a link to egg candling pictures which will give you a good idea what you should be seeing when you candle. I used it a lot last year!! It will help you tremendously.
https://www.backyardchickens.com/forum/viewtopic.php?id=261876
Best of luck with your hatch!! Don't worry about the eggs cooling a bit while you candle, remember that hens get off the nest to eat, drink and poo every day. The eggs will be fine.
Brinsea has even put out research saying that periodic cooling is good for hatch rates and they are building new incubators to have cooling periods.
http://www.brinsea.co.uk/cooling/ They are tougher than we know.
Good luck!!