I took my son out when he was 3 days old & he was fine.
Dr will recommend you wait until they have their shots, after that just dress them appropriately for the heather :)
Ya Ive heard some say its good to take them out so they can get use to the germs. But others say wait a couple weeks. I can't imagine staying in with a newborn for weeks. I just wanna do what's best for baby but its hard to decide. Lol.
I've been taking my son out almost daily since he was a newborn. I live in Scotland so its pretty cold here and he's been fine. Just make sure clothes are weather appropriate and there are blankets in the pram.
I would like to know the same thing I'm due 1-28-14 and I was complaining to my gma about not being able to take the baby out because of all that and she told me " your father was born January 12th and I took him out everywhere and he was just fine" and I have to say it's true lol. But I really don't know some people suggest not taking them out until flu season is over but that's a long time.