Choose a location for the reading nook. An alcove or recess between built-in bookshelves is a good choice, if you have them available in your house. Build your own alcove by placing two bookshelves on either side of a wall corner with space between for the reading nook. A corner of your child's bedroom or the den or family room are other ideas.
Place comfortable seating in the nook. A large beanbag chair is an inexpensive choice that appeals to young children, and thus might encourage your child to use the nook more often. A small armchair is another idea. Add a small blanket and pillow, so that your child can get comfy or even read himself into a nap.
Attach a wall sconce above the seating at a height that is appropriate for your child to use. The nook might be in a place that doesn't receive other lighting, so a good source of light is important. Another idea is to place a small table near the seating with a table lamp on it.
Set up book shelves. If the nook is made with bookshelves, reserve one or two for your child's books. Small wall-hung shelves near the seating keep favorite reads nearby. A small bookcase can double as a lamp and snack table.