How many yards of fabric would I need to make a twin size quilt?

I want to tie quilts for all my nieces and nephews for christmas (there are a lot so I need to start now). I want to make twin sizes so that they can have them on there beds. I am just not sure how many yards of fabric I am going to need for the top or for the bottom. Also wondering what type of batting I need and how much. I also need the size for a crib.