You can buy beer at two places in Ottawa: The Beer Store and the LCBO. The quality of selection will depend on location. The biggest LCBO, and I assume best selection, is at King Edward and Rideau. A Beer Store with good selection is the one on Scott St., near Holland. It's also the kind where you get to pick your own beer versus ordering it, so there's more opportunity for browsing. Actually, you could cruise on over to Hull for a 3rd option. There's a depanneur at Victoria and Laval that has a good selection of Quebec microbrews.