Well, er, for the first two weeks, with my second full-term child, I did the put the baby to sleep lying on mommy's chest thing (kangaroo care always put 'em to sleep right away). Then gently transfer to bassinet while asleep. Combined with the go to sleep while nursing on side in bed thing from time to time. Just until she figured out that night time is sleeping time, and day time is play time. I know, I know, lots of don't sleep in the bed with the baby warnings out there, but sometimes you gotta do whatever works.
My first one I set an alarm every three hours for the first three months, and she never did wake up unless I woke her up to eat.
I second Kara's suggestion of asking about reflux.