Mike, as others have said, it depends. Every climate is different. In my opinion the best way to go is to see what is the most successful in your area. Bees are adaptable and are able to regulate the air flow in their hives to some extent.
Those of us who live in climates with a wide range of temps tend to manipulate the hives temperature by insulating in the winter and allowing more air into the hive in the summer.
One prevalent theory is that hive congestion leads to swarming, and that allowing bigger entrances and more airflow lessons that; Another opinion I have read advocates more airflow to help the bees evaporate the nectar; Yet another opinion is that too much ventilation actually makes it harder, not easier to ventilate the hive. Whats a newbie to do?:scratch:
Back to my beginning point about localities. If you can join a club or visit the yard of a local beek who has been keeping bees successfully you'll pick up many tips which can save you making costly mistakes. Good luck this is a fascinating subject and like all things beekeeping you are going to see a wide range of solutions to the same problem, and a wide range of opinions as to whether it is even a problem.

Adrian.