M.P.
You're going to get a lot of people who will try and tell you it's the wrong way to go but just remember that this is YOUR child, not theirs and what is right for them isn't right for everybody. You aren't even asking for advice about weather you should use cry it out so there should be no responses here trying to sway you. I'm sorry, I just get so annoyed when parents push their parenting styles onto others.
With my son and cry it out he was sleeping through the night (12 hour stretches) at 2 months old. We also had moved him into his own room by then. The trick is to learn to recognize your babys cries. I can tell when my son is crying just because he is fighting his nap or he is really not going to nap (which is more of a scream). I use cry it out for naps and bedtime, though my son doesn't cry at bedtime. His routine has gotten him really ready for bed by the time we put him down.
I guess all I can offer is learn to tell the difference in your childs cries and by letting them cry it out a few nap and bedtime will help you do that.