C.P.
Dear A.,
You need to wait until at least 6 months before trying any kind of cry it out method. A very good friend of mine is a clinical psychologist and an expert in early child development, and according to her, babies are physically incapable of putting themselves to sleep until at least 6 months of age.
I have a fabulous 22 month old son, so we've been through all of this... Your 12 week old baby is not going to sleep through the night no matter what you do. If he does start sleeping through the night, it's going to be his thing.. we were lucky and our son slept for 6-7 hours from the time he was 2 months to 6 months. But he hasn't slept through the night since. No matter what you hear, most kids don't sleep well through the entire night until closer to age 3. I know you're getting ready to go back to work so I hate telling you this b/c it's not what you WANT to hear... but you're not going to get much sleep. It's going to be really hard. But you will get through it.
As for the cry-it-out methods... let me tell you also that we tried this for 1 year (Ferber Method) and we did have some success from time to time. But I'm no longer an advocate and I'll explain why... Every time your baby goes through changes (which will happen constantly) his sleep patterns and needs (eating...) will change. Every time you travel or have visitors... every time there's any interuption at all in your normal sleep routine you'll be crying it out all over again. It does not work for the long term. After doing this over and over dozens of time for a year, I finally realized that it's not the answer, and I actually can't believe that this is what most pediatricians advocate (they probably either don't have kids or they have nannies full time that deal with sleep issues). I really only know of 1 friend whose little girl repsonded pretty well to the cry it out method. and I still hear her wailing away upstairs for 45 minutes stretches occasionally. crying is the baby's only means of communication. and you're building a bond of trust during those critical early months together. do yourself a favor and buy the "no cry sleep solution" and try following some the wonderful ideas you'll read about establishing good bedtime routines. We started this last summer when we moved our son into a big boy bed and we've had no crying at all and nothing but success. AND we didn't have to listen to him cry for hours on end to no avail... everyone wins.
I hope this helps. I sincerely believed that Ferber was the right thing to do... but I've completely changed my mind. and like I said, we tried it religiously for an entire year before basically throwing the book out the window. it was so ridiculous. there are so many other factors at play... hunger, the desire to just be comforted eating and falling asleep... once you begin to address those issues (around 6 months is a good time to begin) the rest will fall into place gradually. And maybe you'll be lucky and your little guy will start sleeping longer on his own. It does happen. Just not as frequently as people would have you believe!
Take care,
C.