One of my favorite artist is Maude Lewis, an impoverished woman from The Anapolis Valley in Nova Scotia. She died in 1973 but left her mark on the world through vibrant, child-like paintings. They're the type of paintings that are perfect to teach to kids because they are non-threatening and often don't employ standard artists techniques. Kids love the simple lines, bold colors and whimsical scenes. For my students in California, the snow scenes and ones that include fishing boats and lighthouses are usually the most popular.
I use tempera paints for simplicity but acrylics would be great and would give the teacher an opportunity to teach acrylic techniques. The basic technique for creating a Maude Lewis style painting is "layering". I discussed the background and foreground with the kids and explained how Maude Lewis might have gone about painting these scenes. How the background shoyuld be painted before the small details like trees, flowers are done.