Good question. Traditional bread can be around 15g of carbs or more per slice.
There are lots of alternatives to bread such as Flatout Light wraps that only have 6g of net carbs. However, if you want real bread you're going to have to hunt. If you're ok with ordering online, Julian Bakery specializes in low carb bread. It's pretty good stuff at only 1g net carb a slice. However, it's quite expensive. Plus, you have to pay for shipping.
If you're like me and want to find a solution at the normal grocery store, look no further than Sara Lee Delightful 100% Whole Wheat with Honey bread. This stuff is pretty impressive. It's still light and fluffy and only has 9g of net carbs in two slices. I found this at my local grocery store. Make sure to get the exact kind mentioned here, though, because the other Delightful breads have more carbs.
There are also Delightful buns with a similar number of carbs. Score!
If you have a bread machine, I have successfully made this low carb bread recipe. It works out to around 3.5g carbs per slice. It's not bad bread, but it does have a slightly spongy feel.
Besides bread, if you like bake mixes, Atkins makes this bake mix for making cookies, pancakes, and other things that would otherwise contain high carb flour.
Have you found any low carb bread/flour products that you like? Post about them in the comments!