I came across a great little book for kids on Kindle today. It's one of those book that offer a whole lot for a tiny investment. It's called "Art for Kids", and it basically covers the elements of art in a simple, illustrated format. It's quite appropriate for grade school kids, and while some of these topics might be covered as kids enter 7th and 8th grade, most schools will only touch on each topic briefly. This offers a great review for some, and a decently in-depth lesson plan for others.
Whether your kid is home-schooled and they need a good introduction to the elements of art, or they are an aspiring artist hoping to learn more than they can in school, this is a great option. I'm looking forward to the next books in the series!
You can check it out here: