Holly Knott has the best advice out there on photgraphing quilts. Most entry requirements will specify what they want for photographs so pay close attention to that for the details.
http://hollyknott.com/stq/index.htm
You'll want it straight on, hanging in good light, so it's not keystoned or oddly colored. Usually one of the full quilt and at least one detail shot. If the photos are being used for jurying into a show, you want to make sure they're the very best they can be.