If you're just starting, I wouldn't worry about getting a "ruler" made from Lowes or somewhere. It won't have the markings you need to straighten and measure your fabric. I agree that the 12" sq. and 6x24" are basics. You can manager with just them for a long time. As your quilting progresses, you can see what you will need more often, but I'd advise you not to buy a pile of rulers, just wait and see.