As for crying and colic, I suggest reading up on all the new baby forums here on MDC. You can get a wealth of experience from other people, and maybe ask a few of your own questions ahead of time. (Try the sleep forum, breastfeeding forum, life with a babe, and the ddcs with newborns). It's repeated ad nausem on the gentle discipline forum, but not as much with babies...expect them to act their age. Expect a baby. One that cries, and is awake all night, and doesn't nurse well, and ruins every single outfit you put on them. And then, when the baby turns out to be easier than that, it will be a pleasant surprise. A lot of people have a lot of unreasonable expectations, and then feel like a failure when they can't achieve them. Expect it to be hard, then you can be thankful when it's not.
PPD. I would be very proactive about this one. Figure out ways that you can make your household the most effecient NOW, so that you can dedicate any time you have to rest and your baby. As a military wife, and a Mama of 4, ages 5 and under, I have found it to be absolutely necessary to streamline my life. Everything I do needs to be as simple and quick as possible. It's worth it to put a little time and money into organization, etc. After the baby comes, I would make these things a very, very strict priority: sleep (not just rest...sleep), vitamins (iron and B complex especially), social time (don't let yourself get lonely or isolated), and you time (take a shower daily, etc. eat and drink plenty. you still need lots of water and lots of protein.)
Deployments. BTDT. We've had 3 deployments and 4 babies in 5.5 years. He'll be leaving for 2 months when our newborn is a month old. Counting all his training, he's been gone a little more than half of the time since our first was born. Here's what I've learned:
1. It's only as big of a deal as you make it. Be matter of fact with yourself and your children, and your life will just be what it is. Don't try to make it something it's not, and don't feel guilty when well-meaning people offer sympathy when your dh is gone. This is YOUR life, and it's okay. Don't feel like you have to mold yourself into feeling bad that your ds doesn't see your dh every day, etc. It's not your norm, and your children won't be scarred for life by it. My children are MUCH more bonded to my dh that most children/daddy combinations I've seen. It's about who the Daddy is, not what he does for a living.
2. Dh left on his first deployment 16 days before our first was born. She was almost 7 months old when he got home, and it was obviously she "recognized" him. The look on her face was the same as a newborn looking at its parents for the first time. They had no trouble bonding whatsoever. I showed her pictures of him ALL the time, and talked about him ALL the time. Daddy was always an exciting fun thing to her. (I work really hard to make sure he STILL is, and to all our children. Daddy means party to them.)
He read books on tape that I could play in the car, and I also played them while I was nursing. I figured that she would be associating something pleasant with his voice that way. I was also carefully relaxed about their meeting because I didn't want to project any tension on her. Oh, and we made a "Daddy book". We took pictures of him all over the house, doing regular things, so she could see him in our regular life. I've heard of children getting confused because the only pictures they ever see of Daddy is in uniform. So, we took lots, and in different clothes. We put words with the pictures (just slipped them all in a small photo album) to describe to her who Daddy is. We talked about things he liked to do and eat. Things that were important to him. I took pictures of when he left and included those in the book. In very simple terms, I explained where Daddy was and what he was doing. It turned out that one of the pics I took looked like he was getting off the bus instead of on, so I used that to talk about when he was coming home. There were lots of assurances all through the book of how much he loved her, and of the things he'd do with her when he got home. I know she was tiny, but she understood far more than we thought she would.
When she was 18 months and he left the second time, we had also made videos of him reading to her, and playing with her. The reading thing is commonly suggested, but, and also according to our friends, our children have responded much better to the videos of him actually playing with them. They remember it and really identify.
We've done similar things through each deployment and separation, and our children DO know their Daddy. We've had ZERO adjustment issues. Well, expect a few weeks of cranky...the sort of ambiguous fussing teething might bring...when dh leaves and when he comes back.
You CAN do this. You CAN do the baby thing, and you CAN do the deployment thing. Embrace who you are, and your challenges. It's what makes life good.