sleep books - do they deal with napping?

I'm trying to get DS into a better napping routine. Right now he just falls asleep in his swing or crib and everyone keeps telling me that I need to get him to nap in his crib.

well, I tried and he cried bloody murder.

Do the sleep books deal with napping issues? He goes down fine in his crib at night.

Also, at what age do you let them CIO?

Thanks!

Re: sleep books - do they deal with napping?

The book I have does, it basically tells you to incorporate a similar, but shorter routine as what you do at night. Its called Sleeping Through the Night by Jodi Mindell.