If you have a piece of wood, you can make a bookshelf. Of course, it will require some time, tools, necessary skills, maybe even a paint or screws. It may not be worth it, especially if you can buy a self-assemble shelf in a nearest Walmart.
Still many people would love to make their own bookshelf. Maybe they already have the necessary tools in their closet or they can borrow them from a neighbor. But they are afraid to think about it because they have heard that you need to be a certified carpenter to do this job, otherwise it is illegal. I say, don't believe it if told so by a carpenter business association.
