Your babies NEED you and crying is the ONLY way for them to let you know... please do not even think about letting them cry it out at this early an age (or later for that matter). Babies go thru growth spurts where they MAY NEED TO EAT AT NIGHT! NEVER assume your babies aren't hungry or don't need you.
I agree that the book Babywise should NOT be followed... I despise that book. I am absolutely against CIO and feel that it is not a proper way to "teach our babies to sleep thru the night". We don't "teach" our babies to eat or go to the bathroom... so why are we expected to teach our babies to sleep?
Amidst all this I DO HAVE A SUGGESTION... Here is what I did for my beautiful baby girl to help her differenciate between night and day...
For the 1st 6 months we co-slept sooo during the day she would nap in her bouncy seat or swing or somewhere that was NOT in our room. When it was time for bed we would stick to the same routine... Bath time, Nursing, night time music, bed time. We would ONLY put her in our room to sleep when it was bed time so she would begin to see that there was a difference between night and day.
ALSO during the day I would wake her to nurse if she slept longer than 2 1/2-3 hours. That way she would see it was day time and she needed to eat that often. At night I let her wake me to breastfeed.
Up until her growth spurt at 6 months she was sleeping 8-9 hours/night!!!!
After her 6-month growth spurt she began to wake up every couple hours again... I tended to her when she cried (if she fussed for a bit I would wait a couple minutes to see if she would fall asleep). Most of the time she would fall back asleep on her own and if she began to cry I would either nurse her or rock her back to sleep (or my husband would rock her back to sleep).
Here we are and she is a year old and sleeping GREAT!!!! All it took was love and reassurance that her mommy and daddy are always here for her!! :)
*Of course to this day if she wakes up CRYING her daddy or I are right there for her.
I know it is tiring, but it WILL get better! Do they sleep in the same crib? I think sticking to a night time routine is key... not matter what time you do it, try to do the same things to let them know it's bed time. Also maybe make it quiet time a half-hour before you begin the routine... that way they can begin to wind down in time for bed!
Just think... one day they're going to be older and they're not going to want you hugging them all the time! take advantage now! :)