Having recently taught myself to draw (somewhat) I know where you're coming from. From a design perspective this is a super challenging problem though.

I actually spent a while trying to come up with an introduction to the app that would do a drawing tutorial of sorts. (Along the lines of http://www.drawastickman.com/episode1) - but the line between the app telling you what to do and guiding you is very thin, especially in content creation software. In the end I decided that it was best to try and build motivation and a personal connection through more subdued means, and that that method would be "truer" and deeper as well.

This is the same reasoning behind not having sample artwork within the program, not even as a tutorial. I didn't want people to open it up and see anything that they had not chosen to create.

I don't know what the proper solution to what you're asking would be - I want it to exist in theory, but I can't convince myself that it would be good in practice.