Ask HN: Suggest an online data visualization course?

I'm a high school math and science teacher, and I need to take a couple courses this summer to maintain my teaching certificate. I want to gain a better understanding of working with interesting data sets, and generating visualizations. I'd like to do better visualization work with students, and I'd like to collaborate with scientists as well. I live in Alaska, so there's lots of interesting science work being done that would welcome some assistance with data analysis and visualization. I'm aware of many online options - coursera, udacity, mit, etc, but I'm not clear on which ones certify completion in a way that's likely to be accepted for credit. I'll probably need to petition my state ed department to accept the credits. Can someone recommend where to look for courses that are likely to offer acceptable credits?