I'm inclined to leave the technical aspects of online pedagogy and teaching tools to those who, like Zellner and Katherine O'Flaherty (whose piece on Blackboard you can read here), have greater experience and expertise than I.  What I want to talk about here is whether or not online teaching makes sense for you as you strategize your trajectory through graduate school and into whatever professional future compels you.  So this is not about how to do it better, this is about whether, as a graduate student, to do it at all.  As with most questions you encounter in this business, there is no definitive answer—merely a disjointed collection of more questions and things to think about.