I could have written this post!! DS is 10mo and I've always bf him to sleep, at bedtime, nap time, and whenever he wakes at night. A few months ago he stopped always going back to sleep, and if he did, he would always wake and cry when I put him back down in his cot, and was inconsolable. He was waking about 3 times a night almost every night since birth basically.
I tried some of the suggestions in Elizabeth Pantley No Cry Sleep Solution. Been doing it about a week/10 days. First couple of nights DS took 1.5hr to fall asleep with help from me (but not bfing). A few nights in he was down to 30 mins, now he falls asleep in minutes. I'm still in the room with him when he settles himself, but he now comes off the boob on his own, as if he knows whats coming and he's ready to put himself to sleep in his cot.
Basically you do as normal - feed/rock/cuddle/sing to sleep, but just before they drop off, you put them down. If they cry, pick them up and do it again, putting them down again just before they drop off. The next stage is you put them down more awake, and stay with them til they fall asleep, picking up etc when they cry. Eventually you should be able to get to the stage where you put them down awake say goodnight and let them fall asleep on their own, and if they wake you can just comfort them without picking them up. We're not quite there yet...and I still feed him to sleep when he wakes in the night. However, now that he basically puts himself to sleep at bedtime he wakes up less frequently at night time, we've gone from waking every 2-3 hrs to now sleeping 4-5 hours and going straight back to sleep when I feed him. I still feed him to sleep for his naps during the day because I can only deal with one bad habit at once ;-)
Good luck!