I buy quite a bit of fabric online and some thread. My favorite online shops are:
www.connectingthreads.com (fabric, kits and thread)
www.fabric.com (fabric and sewing/quilting notions as they have good sales.
www.keepsakequilting.com (expensive, but they have good sales and a wonderful selections)
www.hancocks-paducah.com (wonderful selection of fabrics, expensive, but sometimes have good sales.
www.joann.com (good sales/ and good coupons for full priced items.