One thing I've been asked over and over regarding preparations for a shoot is "What do I need to do for my baby's photoshoot?" and the answer is really quite simple!
First, about an hour before the photographer is due to show up at your house, you should turn up your thermostat. I have found that warm babies are happy babies, and since your little one will spend a good portion of the shoot wearing nothing but a hat, 75deg is a good point to start.
Second, keep the baby up as much as you can in the hour or more leading up to the shoot - you don't want your baby to be on the verge of waking from a nap when it's time to photograph them sleepy. I suggest, for a newborn, wake them for at least an hour before the shoot, try everything to keep them awake!
Third, have on hand anything special you want to include in the shoot. Is there anything that you had in your maternity shoot that you want to carry to the newborn shoot? Is there a teddy bear you had when you were a child that you're passing on? A blanket for the new babe? All these little props will make your session that much more special. I, of course, will come with hats, cocoons, bowls, baskets etc... but the personal touches are what makes it special!
Last, try and relax! I'm not in any hurry when I come to your house. If the baby is fussy, take your time in soothing him or her. Feed your child when they need to be fed, cuddle them if they need a cuddle. Most importantly, like I mentioned earlier, a happy and comfortable child will be happier, sleepier and squishier in the photos, which is generally what we're looking for!