The Brew Mentor at 9528 Diamond Centre Drive, Mentor, Ohio.

My favorite place to buy grains and other brewing supplies. They have a great selection of grains and adjuncts, and a good selection of yeast and hops as well. The staff is always very helpful with substitutions if they don't carry a certain strain of hops or yeast, and are also willing to order anything not in stock at your request. Bulk grains here are a great deal and cheaper than any homebrew store I've ever seen, and also cheaper than buying online once you factor in shipping cost.