You could start with Judy Hopkins' "501 Rotary Cut Quilt Blocks". It has directions for multiple sizes of blocks, from about 4" up to 12", and some even larger. It shows just what size to cut, how to cut and so on. I used it just last week to design my blocks for my longarm challenge.
Now I have to quilt it... as soon as I manage to leave work early enough to pick up some batting at the LQS.