Hi J.,
I had major problems getting my child to nap in her crib and sleep all night mainly because I used to nurse her to sleep and she did not know how to go to sleep on her own she would sleep on me just fine and that is how I was letting her take her naps.
I tried everything from trying to put her down drowsy, laying down and sleeping with her to letting her cry it out.
Finally, when she was 14 months I found a great book called "Good Night, Sleep Tight" by Kim West. I had been trying to wean her and was having major difficulties weaning her because of her sleep issues.
This book helped me BIG TIME. Do not get me wrong, it was not easy, but I was determined to stick with it and it has worked.
Basically, it is a book that is a gentler method to just letting cry it out alone. You get her to lay down in her crib on her own and stay in there with her until she goes to sleep. My child threw tantrums and it took me almost two hours to get her to sleep for the first few days but it got easier.
I had to do a modified version because my child was used to being nursed to sleep, so I rubbed on her to get her to sleep and after I she got used to being rubbed to sleep, then I rubbed her a little less and a little less until I finally made her go to sleep on her own and it was much easier that way.
Now, my child takes two naps a day in her crib and for the most part she sleeps all night and has been completely weaned. It has taken me over a month to get to this point, especially not crying and throwing tantrums when I put her down. She is 15 1/2 months now.
It is going to take you being determined to follow through with it. I hope this helps because I was to my wits end when I finally found this book and now I am so much happier and so is my child. I would definately cut your child down to two naps even if you do not want to use this approach. Good Luck.