Screencasting

Screencasting tools (教学视频) can be used to upload teaching videos on the web, to enable students to access teaching materials anytime and anywhere, to pace students' learning and to help students achieve self-directed learning.

1) Powerpoint is the simplest tool you can use to record slides and voice narration. However, you can't edit the powerpoint show.

2)  Camtasia Studio can record Powerpoint slides and is rather easier to use. You can also edit the video. Here's one I recorded, not the best, one of the earliest video I recorded for a trial.