We didn't start co-sleeping right away. Our son's bedroom is right next door to ours; there are about ten steps from the edge of my bed to the edge of his crib. My husband was pretty adamant that he stay in his own room - I was on the fence about it, but figured that was the right way to go - that's why you have nurseries, right? Segregate your sleeping spaces, and everyone gets a good night's sleep.
It didn't exactly pan out that way. At about six weeks of age, the Munchkin got sick. He would only sleep in his crib for about an hour when we'd put him down, and then he'd be up and crying and need nursing, singing and soothing to get back to sleep. Of course, when you're sick, sleep is all-important, especially to a baby. When he slept on my lap, however, he'd stay down for two to three hours at a stretch, so I started holding him for naps.
I was so tired, that my husband would take him as soon as he got home, and let me get some sleep. One night, I had my hubby bring the baby to me to nurse in bed at around 7:00, and he ended up sleeping next to me until the morning; that was the first time he slept through the night. I remember waking up and doing a double-take when I saw the clock. Thus, our co-sleeping arrangement was born.
I don't move when I sleep - never have. Whatever position I'm in when I fall asleep is the position I'll be in when I wake up. My husband's a flipper, though. When we sleep, my body is in between the hubby and the baby as a shield. We have a firm, wedge-shaped pillow that the baby's on (so milk doesn't come out of his nose when he nurses); I'm on his right, sleeping on my left side, with my Tempurpedic pillow above and to the right of Munchkin's head. My left arm threads under this pillow and above the baby; my right hand is either against my side or resting lightly on his middle. And there we sleep throughout the night, the baby safe and warm beside me.
I'll admit I was a bit nervous at first, because Munchkin was so little. He was just a bit over 4 1/2 pounds at birth; by six weeks, he wasn't quite yet 7 pounds. We got a physical co-sleeper, the kind that sidecars to the bed, but we've never actually used it. After the first couple of co-sleeping naps all in the same space, it was clear I wasn't going to roll on him - one time Daddy got a little too close, and the baby reached up and bopped him on the nose really hard. He's tougher than he looks.
The best thing about this whole arrangement is that all three of us get a significant amount of sleep. No more running in the middle of the night to soothe a crying infant; in fact, he rarely cries at all. If Munchkin needs to nurse in the middle of the night, he can actually latch himself on, which is hilarious to watch - an eyes-closed, completely blind search-search-search-CHOMP <slurp-slurp-slurp>. Sometimes I wake up to find him nursing happily away, and I've been none the wiser.
Our setup is not for everyone. If you're such a mover and a shaker that in a deep sleep, you might actually squish the baby, then I don't recommend it. Similarly, if you like to get a little tipsy before bed, or need pills to get to sleep, this is not for you. But all over the world, and for centuries, people have been sleeping with their children like this. He's not alone, he knows he's safe and warm, and if he needs a midnight snack, the "fridge" is within arm's reach. I'm actually going to be very sad when it comes time to move him to a big-boy bed, and I'm left without my little snuggle puppy. (His Daddy's a good snuggler, too, but that's different.) My son will need his independence at some point. For now, I'm content to be his security blanket, watching over him so we can all get a good night's sleep.