From what I understand (gf just finished her education degree, michigan secondary ed), there isn't really a teachers certification for computer programming/CS classes in secondary. It is generally taught by someone who shows interest in teaching it AND if there is an opening for the class in the schedule AND if there is a budget to allow that elective AND it doesn't get in the way of whatever the school's administration deems to be important. The state of it is quite sad really...I know at the high school I graduated from, there was a programming course that was taught by the typing teacher, at one point (was no longer available by the time I would have been able to take it).