I am actually, in general, a fan of CIO if it helps the child to form good sleep habits that will last a lifetime.
In your case, though, I don't think you've been home long enough to start. Do you know what kind of routine your son was on before you picked him up? If so, I would follow that as much as possible.
As the other poster said, now is just a super important time for you and he to bond and attach...wear him in a baby carrier, hold him and rock him and sing to him and basically do whatever it takes to make it through!! You really have been home a very short time and I think you need to give him a bit more time before focusing so much on scheduling.
Michele