I just bought this book for one of my homeschool teaching students, and it's a fantastic resource! I'm not an artist or art teacher specifically, but I found the book very easy to use. It looks to me like it takes the basics of art and breaks them down into fun and easy activities for each of the topics listed on the cover.
Each activity includes a photo of the activity along with simple instructions, so it's easy to just open the book, look at the activity, and start teaching pretty quickly without a lot of prep (assuming you have the materials, which are mostly materials you'd probably already have, such as paper and colored pencils).
You can view some sample pages on Amazon to see if the book is right for your child. I'll also share some photos from one of the lessons in the book that I did with one of my students. This lesson is about different types of lines.
The first thing I did was fold a paper into three sections, one for each type of line in the lesson (diagonal, vertical, and horizontal). I also copied a page from the book and drew outlines of fish in each section (diagonal, vertical, horizontal). This student has a particular interest in ocean animals, so I wanted to incorporate that into the lesson. Pictured below are the models I drew for the lesson. The student drew his own lines and his own fish on separate pages after I let him watch me draw these lines.
For this activity, we did one section at a time. For example, we did the diagonal lines on the blank paper, then did the worksheet section (with the fish) on diagonal lines. After that, we did both sections on vertical lines, and so on.
Once we'd finished both of these pages, we did an art project based on his interest and using the types of lines. This wasn't in the book; I just wanted to add another activity based on his interests.
You can find the book on Amazon at the link below. I've also linked another book I bought to help me learn more about teaching art.