Hi C.,
I was in the same boat you are- My first born would not sleep unless we rocked her to sleep, then when she woke in the night (sometimes 5 times a night) she would need to be rocked again. I did not sleep for 2 years and I was not able to function very well.
Anyway, we tried EVERYTHING- I read every book out there and at 25 months ended up hiring a sleep consultant. What she said to me was hard to take- it went against everything I felt was right, but I was so exhausted I had to try- and IT WORKED!!!
Basically she said to have a talk with her about how she is growing up and can do things all by herself- give examples- in my daughter's case it was she could go down the slide at the park, and put her shoes on- whatever example you have that will give her a sense of pride that she can do it-
So you tell her, you are such a big girl now, you can use your spoon and drink from a cup and ..... It is time for you to be able to go to sleep all by yourself too. Tonight when it is bed time we are going to have a special routine- we will (insert your routine here) brush your teeth, read 3 books have a little cuddle, and then it will be time to go to bed. When we put you in your crib, you get to lay down all by yourself, close your eyes, and go to sleep. Mommy and Daddy are going to go to sleep in our room and when we wake up in the morning we can all play together again.
If you go over the routine and let her know what to expect a few times during the day then when it is bedtime you can remind her of how proud you are that you know she can do it.
Once you tuck her in, that is it- You do not go back in until the morning.
The first night might be rough, or easier than you thought, usually the 2nd and 3rd nights are the worst, but it gets better pretty quick.
The way to keep yourself sane: Keep a log- write down what time she starts crying, how long it lasts- That way you can see the progress (I know 5 minutes of crying and or screaming can feel like an eternity, but if you look and see that it was 20 minutes tonight, and 30 last night, you can see progress and feel better.
For nap time it is the same thing- Once you put her down, she is on her own for an hour. at the hour mark if she is asleep, great- if not, go and get her- nap time is over.
If she is overtired it will be harder, so put her down a little earlier.
OK- that is all the books I read and the sleep expert's plan in a nutshell- If I had to recommend 1 book it would be Healthy Sleep Habits, Happy Child by Marc Weisbluth (SP?)
It gives a lot of good info for sleep for all ages.
Good luck- For me this is the hardest part of parenting, but once it gets worked out, makes the biggest difference in your whole family's lives.
S.