Hi. I'm new here and am very confused. My name is Linda and I live in Arkansas. I am wanting to knit some caps for Christmas presents and the patterns I've found use circular needles. I bought a box of knitting needles at a yard sale several years ago and there are lots of circular needles in the box, however I can't find a size on them anywhere. How do I tell the size of the needles? And is there any secret to using them?