I just purchase it by the yard, although I have found it in rolls that is perfect for borders. And go for either a grey or white... much easier to see.
Quilters find all sorts of new uses for ordinary things. Toothpicks for turning applique, yardsticks with a magnet attached to pick up stray pins off the floor, how to mold a thimble for your thumb (great for pushing the needle through thick seams), how to use the inserts in bacon packages to use for patterns, etc., etc., etc.
Hang around any quilter and you will learn something in short order. I hope you enjoy quilting. It is one of my life savers and life savors...