I got the pattern here: http://www.crochetme.com/media/p/89123.aspx
I made the small size, as my hips are 38".
I crocheted holding two strands of No. 10 crochet cotton. The skirt squares took almost exactly two spools of thread- I think the spools held about 1000 yards. I had to go back to the store and get a bit more for the waistband. I chose crochet cotton because it looks smoother and shinier than yarn. I also think that yarn would have stretched a bit too much for this skirt. (Note: If you do decide to work with two strands, be warned that crochet cotton gets tangled extremely easily. I may or may not have had experience with this. Also, if you want to use one strand of crochet cotton, you could try to use No. 3. I think that it would be thick enough.)
This is a very lacy pattern, so unless you want to use it as a swim suit cover-up, you probably need some lining. I got 1.5 yards of muslin at Joann, sewed a seam up the side, pleated it in the back, and sewed it into the waistband.
Did I mention the waistband?
It is the only part of this skirt that didn't quite work out right.
Here is a close-up image of the waistband. The instructions say to do a few rows of sc and dc or something. I didn't think that sounded very sturdy, so I disobeyed the instructions and did a double thick row of sc. It looks very slick, and is DEFINITELY sturdy....so sturdy that I have to pull it on over my head. Not the best way of getting dressed, but it works. Anyhow, if I were to make this skirt again I think that I would work out a zipper or a button closure or something, or maybe attach an extra wide piece of elastic instead of making a waistband. Oh well. It is still a pretty awesome skirt.