"I was wondering if you could do an Ask Moxie post about preparing a young one for an impending sibling. My son will be not quite 3.5yo when #2 is expected to arrive this fall and I am looking for tips and tricks on preparing him for this big change. He is a very sensitive little guy who is used to being the focus of our lives, and on top of that he does not handle changes terribly well. I am worried for him, as this will extremely difficult for him process, I think. We have only talked about it briefly so far (I'm still in my 1st trimester) and he gets very serious and sad looking whenever I mention having a baby/sibling in the house. If I ask him outright if he'd like a little bro/sis to play with, he says "No, thank you." I don't want to get too heavy about it with him, but I also don't want to just brush it off and utterly wing it when the time comes."
I know you're really excited about the baby (and congratulations!), but I think it's way too early for your son to really process what that means, and certainly for him to be excited about it. And would you really want him excited about it this early anyway? It would be like one long, nightmarish version of "Are we there yet?" for the last two trimesters until the baby finally showed up.
Realistically, I think your son's not going to start processing it until you're showing, and maybe not even until he can feel the baby start moving. (Since he's 3, he'll probably get it at that point. A toddler won't even process it then.) So I'd focus my energy right now on getting your ducks in a row for what's going to happen during the birth and postpartum period so you have that all set. Then start working on prepping your son once it's a little more concrete for him. You can start mentioning it every once in awhile or reading a book here or there, but don't expect it to connect with him until much later in the process.
You're going to have to figure out where your son will be while you're having the baby, and with whom. If you're leaving your house to have the baby, you'll need to figure out it you want someone coming to your house to stay with your son, or if your son should go stay with that person. Factor in that you might go into labor and need to leave for the hospital or birthing center in the middle of thie night while your son's asleep. If you're having a homebirth, you'll need someone to come take care of your son during the birth. (That person should not be someone who really wants to see the birth, since there's no guarantee that your son will want to be there when it happens. My midwife told me that she'd attended quite a few births in which the older sibling was totally excited for the baby to come, but then noticed that Dora was on and wanted to watch that instead of the birth. C'est la vie. So make sure the person assigned to care for your son isn't invested in seeing the baby come out.) Some likely people to ask are your family or in-laws, close friends, your regular babysitter, or other parents in your playgroup. And don't feel like it's a huge imposition--it's a way people can do you a great kindness and participate in your baby's birth in a concrete and necessary way, so most people will feel honored to be asked.
You're also going to have to figure out who's going to be helping you out after the baby comes. Your physical and emotional recovery will probably be much easier this time, so you won't need as much help with the baby or with yourself. But your older child will need a ton of attention and you simply won't be able to provide it, no matter how much the baby sleeps and how great a carrier you have (although you'll definitely need a great baby carrier so you can strap the baby on and go about your business as much as possible). So think about who you want to come and help you postpartum. For a first baby it's important to have someone you get along with. For a subsequent baby it's important to have someone your older child gets along with--you can put up with a lot of days of an annoying mother or MIL if she runs your older child ragged at the playground all day and makes your older child feel special while you're learning the new baby.
(IME weeks 3-6 were the toughest. My mom had gone home, but the baby was still so needy every second, and my older son was starting to be Not Happy At All about having to wait his turn. In hindsight, I should have hired a postpartum doula to come a couple of times a week for those weeks and asked my part-time babysitter to work a few more afternoons. Other moms of 2+ kids, what weeks did you think were the hardest?)
If your older one will be in school, don't forget to arrange for some help to do drop-off and pick-up.
By the time you've thought all those things through, you'll probably be closer to showing, and your son might be a little more able to connect with the reality of the baby coming. You'll want to open up a dialogue about the baby without bringing it up so often that he'll be sick of it. You also want to make sure that you allow him to have and verbalize his own feelings about the baby, even negative ones. (Our standard line was, and still is, "You don't have to like the baby but you can't hurt him.")
Probably the most popular way of prepping a child for an impending sibling is to read books about having babies. I'd like to give you a long list of our favorite books about a new baby coming, but, well, I can't, because my son didn't want to read them. I got a few out from the library, but he just wasn't that interested in them. I know the readers will come through with good titles, or you can ask the children's librarian for help when you go to the library.
My son was way more interested in looking at pictures of the baby growing inside me. I looked and looked for a kids' book with drawings of the baby growing, but couldn't find one. (I was thinking it would be cool to have one that looked like one of those anatomy coloring books, but simplified a little for kids.) Instead we looked at the drawings inside my pregnancy books (there are some in the Sheila Kitzinger The Complete Book of Pregnancy and Childbirth and in the Martha/William Sears Pregnancy Book) to show how the baby was growing in relation to my body. We also spent some time looking at the cool photos in Lennart Nilsson's A Child is Born. (Although there aren't many good photos of the baby growing after week 20, and you'll have to judge whether your child can handle looking at the photos of the actual birth.)
If your son doesn't already have a doll, now's the time to get one. He can play with the doll now, and it will open up some more conversations about the baby. When the baby arrives he can take care of his doll while you're with the baby. I don't know if girls are as into anatomically correct dolls as boys are, but boys seem to be really into dolls that look like they do. Here's a nice hard nylon one (it comes in boy and girl, black and white). Here's a nice soft fabric one (it comes in boy and girl, white, black, latino, and asian).
We found it extremely helpful to take a sibling preparation class with our son. He got to meet other kids who were going to become big siblings, and the teacher of the class was great in terms of telling the kids what to expect, and in telling us what to expect. There's a pretty specific timeline of the way kids usually act when a new sibling comes. I wrote it up in detail in this post, but basically the older child will act out and get more and more unmanagable as the due date approaches, then relax when the baby is born for a few weeks, then start acting up once the novelty of the baby wears off, but then start to enjoy the baby once the baby is old enough to start crawling.
The largest part of our preparation involved answering questions when my son asked them (ranging from "How did the baby get inside you?" to "Is the baby going to play with my toys?"). In our case, it seemed that my son was OK with the idea of a baby (he liked his friends' siblings) but was apprehensive that the baby would take over his bed, his toys, his friends, and his life. We spent a ton of time talking about how the baby wouldn't be able to move around or play with his stuff, or sleep in his big boy bed. I was careful to allow him to express negative and indifferent feelings about the baby, even once the baby arrived. He still escalated in fears and negative behavior up until the birth, but we knew it was normal and tried to be more gentle with him than usual.
I'm guessing that your son's sensitive nature will be helpful in the process, because he'll be able to express to you what he's afraid of. Instead of keeping it all inside like the "tougher" kids, he'll tell you what he's really afraid of. If he's freaked out, you'll know it, so you'll be able to respond.
Even if you ignore the rest of the advice in this post, definitely read the book Siblings Without Rivalry by Faber and Mazlish. Every parent of more than one child should read this book. Heck, every person who has a sibling should read this book. Everything in it is common sense, but stuff you wouldn't think of on your own. My favorite parts are the section about not allowing your kids to assign themselves roles (even if you're scrupulously careful not to assign roles your kids might do it themselves) and the flowchart about how to know when to step in on an argument and how to know when to let them work it out themselves. The book is in cartoon format, so it's a quick read.
The biggest thing to remember in the whole process is that you're going to feel guilty about changing your son's life. He's been your only guy for so long that it's just natural to feel like you're wrecking his life by having a new baby. My mom says, "The guilt begins as soon as you get pregnant with the second one," and it was definitely true for me. But kids' lives are only enhanced by having siblings (assuming the parents are good parents and don't play favorites). It takes awhile to get over the initial bumps. The first 6-12 months will be hard. You'll feel like a shitty mother. But if you can keep your eyes on the long picture--having kids who like who they are, respect each other, and can work through their own disputes--you'll end up with kids who are thrilled to be each others' siblings.