“Simple, well-designed basic instruction for line drawings”
I can't remember the title, but there used to be a great series of Scholastic books that walked kids stroke by stroke through creating line drawings of animals and monsters. Sadly my own artistic endeavors never got much farther, but thanks to those books, I can still draw a serviceable vampire. Draw With Me is the iPad version of those books, with the added bonus that your kids won't be constantly pestering you for paper. There are three levels of difficulty, each with six line drawings to follow in 3-4 steps. The basic pictures (basketball, apple, pants, etc.) involve anywhere from 6 to 12 lines, and even the advanced pictures don't involve more than 20 lines. The toolbox includes three brush sizes in 17 colors and, most importantly, an undo button. Once you've completed your drawing, you can upload it to Facebook, email it, print it or save it to your iPad photo album. That's really all there is to it - it's a simple, well-designed, single-purpose app that will help kids grasp the concept of step-by-step line drawing, and potentially give them the confidence to start going freehand on paper.
Once your child has mastered a few of the shapes, it's time to go analog. Break out the finger paints to start - an easy transition from the touch screen - and then introduce pencils or brushes. Also, focus on one shape, and then scale up to larger and larger sizes to provide a lesson in maintaining proportions.