[kenni]

I've been volunteering to teach high school kids how to program for the past decade and it's been my job for the past two. As many of the other comments recognise, finding the joy in programming should be your number one goal. Having peers to bounce off of and push each other forward is a great way to do this!

One of the programs we run at work is an online 5 week competition where you learn to code (either with Blocky or Python) at the same time. It's called the NCSS Challenge http://ncss.edu.au/challenge . It's aimed at Australian students, but you can give it a go from anywhere in the world.

Teachers often run the Challenge in their classes and we have had a few code clubs run it too. It works really well having a group of kids be able to compete and encourage each other to solve problems.

There are multiple levels, but it increases in difficulty each week at a challenging but achievable rate. At the hardest levels it gets quite competitive with students making programs to compete at playing games (last year was Big2) against each other.

I'd recommend clicking the "Try demo" button at the bottom of http://ncss.edu.au/challenge . Even if you don't sign up, you can get an idea of what kind of problems we see kids getting hooked by. I think there's a lot you could "steal" in terms of how to pose interesting yet simple and informative problems for teenagers to solve.