Sleep training

Brittany
Is anyone else's baby sleeping just as bad as they did when they were a newborn? She is 9 months old and all the sudden she is sleeping terribly. Since we have to rock her to sleep we know she is not soothing herself back to sleep when she wakes up, so she needs us to rock her back to sleep. We have decided to try sleep training starting tonight and i am so nervous and worried about how it will go. What have y'all done to help your restless baby?