Edible arrangements are AWESOME.. but pricey.
Honestly, if you are within the area to deliver, I wouldn't have flowers sent.. but would hand deliver them instead. You can get a bunch of beautiful flowers for 1/3 the price the florists will charge. If not, I like 1-800-flowers.com.. they've been consistantly good. I try to do plants or a neat tree or something instead of just flowers that will die in a few days.
If you are thinking a gift, I like
www.redenvelope.com, a lot of nice gifts for Mom to be found there.