Ask HN: How would you teach programming to kids?

I have the opportunity to teach programming to kids around the age of 12-14. The idea is to give them the inspiration and basic tools to continue programming on their own until they go to university or start their first job. I was thinking of starting off with a simple project that walks them through the basic concepts and finally end up with something simple but cool and working. I'm wondering if that would be the right approach. If so, would you recommend any particular project or resources? Also, how would you distribute theory vs practice (e.g. 30% theory/70% practice)?