I put ds into his big cot in his own room at 3 weeks old. I made the mistake with my first son of keeping him with us until he was about seven months old...big mistake...he didnt sleep until he was 4 years old.
If he is sleeping well then i would go for it, you may not sleep for the first few nights as you will will be listening for him but you will get used to it.
Its the best thing i ever did, he now goes to sleep in his cot in the dark and i just hope this contiunues, i honestly beleive this is beacuse i put him in the big cot for naps from day one.
Kelly xx