Okay, my dad found a decent store for knitting supplies, so I was wondering what kind of supplies would be useful...Lots of yarn, I know, and needles are a must...but what kind of needles? Is there anything else I should have? I've only got a couple of circular needles and one pair of single points and yarn. I'm asking for an interchangeable set, and double-points. Also, what is that thing that helps determine gauge called?