Here's a question from someone that I can finally feel good about saying "Go for it!  This is a GREAT time for making some changes!" After that volatile period of 8 – 11 months that we've talked about at length, there's a relatively peaceful window between around 12 and 16 months (with the caveat that some kids do start walking around this age and for SOME kids, this can be very disruptive for sleep… but for most, this is a nice, stable stage).

First off, I think it's a great idea, if you can do it, to night-wean before making big changes with the co-sleeping situation. It's not necessary, but it sure makes it a lot easier. To answer your question about when is a good time to go from co- to alone-sleeping, you're just about to enter one of the best windows right now.  Why?

Sleep training at this stage gets a boost from the toddler’s sense of autonomy, he has a new-found interest in the nonsocial world, he's relatively independent and secure, and he's developing a real sense of connection and social power through the beginnings of language. Most children some time during this stage begin to walk and they are SO INTO getting around and exploring… which makes them a little less into you. Many kids this age can bounce back from emotional challenges, they don't need to cling desperately to the image of a recently departed parent. However, sleep training at this age is also hampered by the 1-year old’s savvy. This kid has just emerged from a phase of relatively intense separation distress. Separations are no longer neutral. They are associated with feelings of loss, anxiety, sadness, and frustration. Although the peak intensity of separation reactions has passed by now, such reactions have not disappeared. Not at all. For the rest of his life, the child will never be entirely free of the potential for pain and anxiety that comes with being left alone and the sense of helplessness that goes with it.

As a result, the 12-16-month old toddler may defy your efforts to change his bedtime routine. He WILL whine, or yell, or cry to get you back, aware of the power of his voice to bring you back. Introducing a new stuffed animal into his "new" crib might help. Music to keep him company while he's trying to fall asleep may also help. Bedtime rituals, consisting of stories or songs that emphasize his connection to you and to the world may also be a great way of bridging his day and night. This child, so autonomous an hour ago, needs to connect with you, needs to know that you are still within range. He needs to know that separation is not permanent, and that you’re going to come back of your own accord. He needs to feel your love and your care, to know that he is the object of your attention and concern, and that he can call to you when it’s time for reassurance. When he calls for you, at least at first, it's a good idea to let him know you'll be right there. He's used to you being with him every moment of the night (or with your mother). So, if you can feel the confidence and independence that your child is feeling through the day and trust that he can go through the night with minimal intervention from you, then transitioning him to his own crib is likely to work. As I've said before, the method that you choose to make this transition is up to you.

Many of the pitfalls of sleep training at this age emerge from your child’s spirit and his intelligence. His hands will find a way to make contact with every object on the dresser—that tube of cream, the box of tissues, the baby wipes, the pictures on the wall you thought were out of reach.  Whether on his way to the crib or once in there, he will use every opportunity to play and explore rather than acquiesce to sleep. And he may be clever enough to capture you in his play (I remember the ridiculous game that BOTH my boys got into of throwing their stuffed animals on the floor, one by one, each time screaming "oh-oh mama!" each time forcing me to come back up and toss the animal back. TEN. THOUSAND. TIMES. a night). You may see this as bedtime, but for your toddler it’s just another episode of play time. But whatever the obstacles you encounter, 12-16 months is a far easier time to initiate the shift from co-sleeping to sleeping on his own than either of the periods surrounding it. You just came from a stage of peak separation reactions combined with social referencing,  and you’re about to enter a stage when the toddler’s whole social-emotional world is turned on its head, when defiance and autonomy compete with abject neediness and insecurity.

In terms of the specifics of how long will it take for him to learn to
put himself to sleep and how long until you can sleep in the same room
again, I can't give you a definitive answer. There are huge differences
among kids who transition from co-sleeping to sleeping on their own.
Some have NO PROBLEMS at all, much to the shock of their parents. Some can take more than a month to make the transition slowly. And still others don't make the transition during childhood at all, if the parents decide the change isn't worth the stress and tears. Some kids are most amenable to the more gentle, gradual approaches (for example, you first move the child to a pack and play right next to your bed and hold his hand or rub his back through the night, then move the p & p a bit farther from you every day until the baby is essentially across the room, in his crib). While other children find those techniques ultimately frustrating and confusing, but respond beautifully to a straightforward Ferber-like method of checking in on the child in the crib at increasing intervals.

GOOD LUCK!  Anyone else have good or bad luck sleep training during this stage? What worked or didn't for you?