Avery and I started out with room sharing. I slept on a mattress on the floor in her room so Daddy could get good sleep until she got her days and nights worked out. I discovered that the only way that I could sleep while she slept (as everyone always tells you to do) was if she was either on my chest or cuddled up next to me. So I dozed in the rocking chair with her on my chest, and when I couldn't stay upright any more, we moved to the mattress on the floor and cuddled with each other.
I was PARANOID about S.I.D.S. so I didn't sleep very well those early weeks. From further research, I've discovered that it's actually very safe to bed-share as long as you live in a non-smoking home and you and your partner don't partake of alcohol or drugs (illegal or prescription) that would interfere with natural sleep cycles. The skin-to-skin contact with your baby helps regulate their temperature (overheating being a S.I.D.S. risk factor), and they can hear and feel your heartbeat and breathing. If they wake up or start to move in their sleep, you can respond to them right away and they don't have to wake up fully to nurse, and neither do you!
After about a month, I decided to move back into our bedroom with her room-sharing with me. I put her in on her back in the crib beside the bed so that she was close, but not in the bed with both of us. She started out not doing well. She would fuss and every time I put her back in there after nursing in the night, she would wake up and cry until she was back in my arms. I decided to try swaddling, and that worked well. She slept her first 12 hour night (with food breaks every 2-3 hours) at 5.5 weeks. But after about a week of swaddling, she was back to crying whenever I put her down. This kid loves her freedom!
I got super frustrated because when she slept on her back, she would startle herself awake during her active sleep cycles and then wouldn't go back to sleep and would cry. It got so frustrating! So I started putting her to sleep on her tummy. It was another S.I.D.S. risk factor (something about re-breathing exhaled air and not getting enough oxygen) so I was worried, but I didn't know what else to do. I made sure either Jon or I was awake while she slept like that so that we could check on her, make sure she was breathing and happy, and it worked quite well. I think it was around that point when I decided to co-sleep for real. When we were awake and she was asleep, she would sleep on her tummy in the crib at the foot of the bed (I moved it a little further away when she started sleeping at night) and then when I was ready to sleep (or when Jon, our night owl was ready to sleep) she would come in the bed with us. This worked well for a long time.
I'm an advocate of babies sleeping on their own, however. I love the closeness we have when we co-sleep, but I want Avery to be able to sleep on her own, in her own room and feel secure and safe just like when she's sleeping with me. So from the beginning I tried to have her sleep at least one nap a day in her big crib in her own room. And now at 3 months, she's sleeping at night in her own room as well. I made sure her room is sleep-friendly (i.e. blackout curtains, nightlight, and white noise machine) so whenever I go in there with her and turn the lights off and the white noise machine on, she knows it's time to sleep. I put her down while she's sleepy but awake and let her fall asleep on her own. I let her sleep with a soother (which is actually helpful in the fight against S.I.D.S.) so she can suck to soothe herself.
It was a long road, but we finally figured out what's best for all of us. I respond to her cries immediately, so when she sleeps alone, she knows I'll come when she cries. And she still sleeps at least one stretch of the night in bed with us. So she feels secure, I feel secure, and we get some good sleep with dozy nursing and cuddles. I think it's funny that I agree so strongly with both sleep-training camps, and have found a nice balance for us. My baby is a huge cuddler, but we've managed to give her independence by giving her security and love when she wants/needs it. Overall, it has been a big success! I hope our other kids acclimate this quickly!