When you first bring your baby home from the hospital, they will have their days and nights switched. This sucks. They will sleep all day and be up all night. The reason is, you have been rocking them to sleep all day by walking around. Then at night, when all is calm and mama is sleeping, they have been waking up to party. To reverse this, let them sleep as long as they can through the night without waking, only feeding them when they wake. I promise they won't starve to death, no matter what everyone tells you. During the day, wake them to eat. This will take A LOT of work because when babies are asleep it is almost impossible to wake them, but do it each time you have your feedings scheduled. Even if they are only up for one minute each time, it will start to change their internal clocks.
Babies go though these things called growth spurts. All it basically means is that every once in a while your baby will turn into a food-hungry psycho that wants to do nothing but eat and sleep. Feed them and let them sleep. It doesn't last long, but it makes you feel like a crazy person when you don't know what is happening. They typically happen around these times: 7 days, 10 days, 3 weeks, 6 weeks, 3 months, 6 months and 9 months. They last anywhere from a day to a week. Don't worry, after they are over, they will get back to their regular schedule (or lack thereof).
Never tiptoe around when the baby is sleeping, even in the beginning. The more you do that, the more the baby will get used to sleeping in complete silence and wake to every noise. Be normal when the baby is sleeping: watch TV, play music, vacuum, empty the dishwasher, etc. If you start this way, your baby will sleep through ANYTHING. Our kids could sleep through a dump truck driving through a nitroglycerine plant.
About a week after you give birth, you will have an overwhelming surge of emotions. It isn't happy or sad, exactly, it is just freaking intense. You will cry for about a day or two straight for no reason at all and then be fine. Just know that everyone does this and that it will go away.
If you can stomach it, have your baby sleep in their crib in their room from day one. You will get little sleep and wake up to every peep if they are right by your side. Plus, sleeping on their own develops good sleeping habits. We had a video monitor and turned the sound all the way down. When they are awake enough to actually need you, you will hear them if your room is close enough to theirs.
Remember that the habits you set in the beginning will continue for as long as you let them. Rocking a tiny baby to sleep for every nap is sweet. Rocking a 1-year-old to sleep for every nap is not.
A good thing to know is that most new things you are trying to train your baby to do, from sleeping through the night to going throughout the day without a paci, only take about three days to accomplish. The first day will suck with lots of crying on both of your part, the second day a lot less crying all around, the third day barely any crying and the fourth day everything will just run like clockwork. This is extremely important to know and remember. Sometimes you will be ready to break and go back to bad routines at the first cry on the second day because you are exhausted and feel like a shitty parent. Don't. You can do it. Three days of hell is worth a lifetime of the good habit you are trying to set. Hang in there, mommy!
Even when your baby is sleep trained, they will often start waking in the middle of the night for no reason. Don't worry. This will only last a week or so and go away on its own. It can be caused by teething, a growth spurt, sickness, learning to do something new, etc. Just say, this too shall pass and take a shot of vodka.