I was disappointed to discover today that HGTV removed the extensive online printable directions that accompanied Simply Quilts episode #1129, Make It Simpler Rotary Cutting. I'm sorry to have left people floundering.
You should know that one square of fabric will yield one quilt block. The benefit is in knowing that if you want to make a quilt of 36 Square on Point blocks, you'd need 36 assorted fabric squares. A quilt of 100 blocks calls for 100 assorted fabric squares.
The fabric squares must be cut to the same size. Whatever size you choose, you must create a cutting pattern specific to that size. For example, 6 inch fabric squares require you to begin by drawing a 6 inch square on graph paper. A finished block will always measure 1-1/4 inches smaller than the fabric square.
The good news is that I amplified and improved my technique with a cutting pattern/top piecing pattern in the book "Rotary Cutting Revolution." I devoted 8 out of 128 pages to it with over 30 photographs. Perhaps you can locate a copy through your local library. The 'new' way means not having to mark your rotary mat nor cutting fabric squares to the exact size to start. You do need a 'straight edge' to cut but you don't need to read the lines on a ruler.
I confess to having many quilting notions and tools, but I write for the person who may have only one ordinary ruler, mat and cutter and is averse to wasting fabric.
Anita
http://makeitsimpler.blogspot.com