It's pretty cool! :)
The lessons vary in usefulness from person to person. As an example; I love the lesson where you're taught how to make a wave, learning techniques in light and shade in water, whereas I greatly dislike the lesson where you have to draw a dog in pencil (I am utterly hopeless at it). But, despite the varying thoughts, you can still learn from your mistakes and redo the exercise, you don't have to complete it before going again. The lessons do get pretty hard though, the last one can get pretty frustrating.
The resources you can use are helpful for future exercises. You can make your own colours of paint by mixing the pre-set basics (red, green, white etc), and there's a colour wheel to help you with finding the right colour. You can zoom in and out for fine detail, and there's even a grid so you can match your artwork to the one you're trying to mimic (You can view photos from the game/DSi camera system for artwork inspiration).
Despite the usefulness of the resources, there are only paints and pencils. I would have enjoyed some pastels/crayons and markers/pen, that would have broadened the range of which type of art you could create.
Overall it was pleasing and I score it 8/10.