I have a young friend who likes to draw, I think he's around 8 or 9. I've been encouraging him to draw regularly and to draw a little from life, and I hope to be a positive force in his drawing journey. Anyways, I want to get him a drawing instruction book for his birthday, I have very little experience with art books so I'm hoping someone here has some ideas. Basically I want a book that will start to give him some understanding of the fundamentals, but it needs to be easy, fun, and beginner/kid friendly. The last thing I want to do is stress him out or make drawing not fun to him.

Also, he mainly draws vehicles, so ideally the book would be centered around that somewhat.

Any ideas would be very helpful!