- The first on - http://www.baseballdailydigest.com/2010/06/09/stras-wars-i-a-new-hope/ - is a good primer and overview along with pre-foot strike details.
- The second - http://www.baseballdailydigest.com/2010/06/10/stras-wars-ii-the-prior-strikes-back/ - is more detailed and focuses on what happens after the front foot lands.
Excellent to read for the overall mechanical elements, but they can also be fairly approachable teaching tools for young boys because of the pictures and the basics of what they are discussing.
I won't steal any of the pictures from the links, but they are quite good. The second picture in the second link is possibly the best of them all.
You hear "keep your weight back" a lot when you are a hitter, and some as a pitcher. What I was never taught was that my body should be back and not rotated to home when my front foot hits. As the links point out, keeping your shoulders facing towards the respective baselines is critical for velocity.