
So, what is...
worsted-weight yarn?
Fingering weight yarn?
the difference between a skein, a hank and a ball (I thought it was all balls

When I've been looking at yarn online in order to get a rough idea of the cost of a project, it talks about ply and double knit, but it doesn't mention that in my crochet books. So can someone interpret please, and if there's anything else you think of that might trip me up, please do tell. I'm a complete noob to pattern-reading.