I have a sunbonnet sue pattern that I want to turn into a rag quilt. Do I just need to cut the pattern with a half-inch seam allowance? Or is there some secret to rag quilting I don't know about? Any info would be appreciated.

The main secret is the fabric. Flannels work best. Regular cottons don't bloom as nicely.

do i use flannel for all 3 layers of the quilt? and it is one half inch seam allowance? thanks for the reply as I am self-taught ---books & tv. this is a great website.

It's preference. I prefer a one inch seam allowance if the block is in the 8 inch or larger range. Under that 1/2" is o.k. Flannel for 3 layers is fine or you can put batting in the middle. Or even 2 layers of flannel if you don't want a warm quilt. It's really up to you.

If you use batting, it is cut the size of the finished block and sewn inside the block. It doesn't hang out.