Another pinner said "Eight common practices that cause problems sleeping through the night, and how to avoid them. hey New mommies out there PIN THIS!! This is exactly how I have put my baby to sleep, she is 18 mos now and she practically puts her self to bed."
I read this book when my baby was 6 weeks and he was sleeping through the night by 9 weeks. Had to tweak the suggestions a bit to fit into our family schedule. It gives advice on getting mutiples to sleep through the night, as well. Definitely worth a try, it sure worked for us!