I would tend to comfort him since it is his first day. I find sometimes they need a bit more help during the first week and then you can start letting them go to sleep on their own once they are more comfortable. The oldest child I've ever had start was 20 months and I had to hold him and give him cuddles for the first day or two and then put him in bed when he was pretty much asleep...after that he had no problem and is still my best sleep at almost 3I don't have experience with them napping all in one room, so I can't help you there...but maybe if you could keep them separate for the first while until they are all used to being with you, that might help. Personally, I never start kids within less than 2 weeks of each other because it takes time for each one to adjust and for you to get to know them etc. Good luck!