The height of the shelves represents a chief concern for a 7 year old. For him to use the shelves effectively, he must reach them. You can find shelf units that only stand about 3- or 4-feet high at the most, which will allow him to reach items such as toys or storybooks with ease. Look for shelves of this height that are sturdy in build. As a bonus, buy wooden shelves that can be painted or decoupaged with images of his favorite superhero characters to add a more personal touch to the space.
If your 7 year old has won quite a few trophies for sports like softball or soccer, hang a few wall shelves to display these items. Because of what they will hold, it's fine if these shelves are more out of reach, which will cut down on the temptation to pull the items off the shelves to handle them, thus not only avoiding ruining the trophies but also preventing the shelves from falling on the young man's head. You can use standard free-floating wall shelves for this project or make a boy-friendly set of shelves by hanging something like a skateboard on the wall using regular shelf brackets.
Built-in shelving in a 7 year old boy's room offers a number of advantages besides having a set of shelves that are ready to go. By their design, these shelves won't topple over, making them safer for a kid's room. You also don't have to buy additional shelves, which saves you money.
The best shelves for a 7 year old boy won't be of much use if he doesn't have some method of organizing them. Several methods exist for helping your 7 year old with this task. Creative Homemaking website suggests that you try using color coding for different items, such as blue for books or green for games. Additionally, provide your son with baskets that he can put items in and place on the shelves. Color code these as well.