my baby slept by herself from the time she came from the hospital...she was always a deep sleeper and never moved when put to sleep - whether she was snuggled up in her magical blankie or not so we were not really concerned about SIDS cause she never moved. i think you really need to see what kind of a sleeper your baby is before you decide to leave them in a room by himself.....that being said, it is easier to start early than later before they realize that sleeping with mommy is much better than sleeping along. small steps to make your baby get used to the new bed / environment will go a long way (such as using the "new" bed for naps initially)...good luck! 