Go here to see the sessions available for your timezone. And here to verify that your computer is set up so that you can participate. (You won't need a microphone or webcam.)
Look under 'Sessions' in the main menu, then 'All sessions' for tracks for teachers, students, policy and so on. There is a huge variety of offerings for teachers.
If you have never participated in an on-line seminar or course then this is a good way to try this kind of thing out. All sessions use the same software, namely Elluminate.