this is one of those things that you have to look into your mamas instinct for, not in a book written by some doctor that doesnt know your baby, and it doesnt matter how much experience he has because its not better than a mothers instinct when it comes down to this sort of thing.
with my first two kids i did attachment parenting, we slept with our kids and we all slept GREAT! i was a heavy sleeper then so it worked out, because i would just automatically put my baby on the breast when they woke up at night.
but with my third little guy, for some reason i couldnt sleep anymore when he was in the bed with us (by now our older kids are in their own beds) so i tried to breastfeed him at night and put him back down, that was horrible! no sleep whatsoever! i was the crankiest mama! so i figured out that he loves to swing so much that he falls right to sleep once he is in the swing. so i tried putting him in there at night, and he slept all night long! he also slept there for naps. he didnt even want to feed during the night, but boy was he hungry in the morning! so i started to feed him an extra serving at dinner before he went to bed. and he did great again! so we used that for a while until he got sick of it then we put him in a little crib and now he still sleeps all night and hes so good about it too, he is 11 months now and we started this at about 7 months. i think he didnt like the bed or crib at first because he was having acid reflux and it hurt to lie down.
sometimes you need to let them cry and sometimes it doesnt work to do that.
this is what worked for our little ones, you have to find out what works for yours! and im sure you realized by now that every child is so different!
good luck!