When I taught 3rd grade I used Mrs. Brown’s Art Class website a lot for art lesson ideas. Mrs. Brown is an art teacher at Hemenway Elementary School. Each lesson has an example image, materials needed, and learning objectives. There is a great FAQ page with lots of good answers to common questions about teaching art. Mrs. Brown has a bunch of art lessons starting at Kindergarden to 5th grade. I encourage you to check out Mrs. Brown’s art resources.
“Like” Mrs. Brown’s Art Class Facebook page to keep up with all of her new art ideas.