what info exactly do you need? typically you're going to want about 5 yds if you're of average-ish build in order to do cross-carries. if you're fluffy or you want to do taiwanese carries or other carries that require extra length, perhaps as much as 6 yds.
lots of fabrics will do for a DIY wrap - cotton gauze/crinkle cotton is nice and lightweight, good for summer. stretchy jersey is good for newborns and small infants. or sometimes they have nice woven fabric in the home decor section - everyone over at TBW is talking a lot about Osnaberg fabric, i know they sell it at Joann's, it's supposed to be a good DIY wrap fabric, so you might want to ask someone about it when you get to the fabric shop?
your wrap will need to be 28-32 inches wide ideally, so if you can find fabric 2x that width, you'll be able to cut lengthwise down the center and get two wraps from it. otherwise you'll need to cut the width you want and use the rest for something else. you should wash the fabric before you cut it to make sure it doesn't shrink a lot width-wise before you cut, also.
HTH! have fun fabric shopping!
