K.B.
I have a 10 month old who has gone through many stages of sleeping/waking during the night. Just when we think we have things figured out, he'll start waking up again! We've been told that this is totally normal--lots of things can make babies change their night routines, like teething, sickness, new developmental stage like crawling, etc. When our son learned to stand up in his crib, we went through a 3 week period of him waking up every 2 hours, even though he had been sleeping through the night before that! We tried all the techniques, including cry it out, but nothing worked. He just eventually learned to deal with the standing up thing on his own.
Our son falls asleep nursing at night too. People sometimes say you should wake them up before putting them down in the crib so he can learn to put himself to sleep, but I don't think that's necessary. For practice, I try to put him down when he is just barely falling asleep at nap time. He can put himself back to sleep at night when he wakes up and isn't hungry, so I don't think it's too much of an issue.
Good luck and hang in there--after our exhausting 3 week stretch of waking, our son is back to just waking up once to eat. Whew!