Great advice and HOW-TOs from the prime practioner of screencasts!
All this, of course, is purely academic if you don't run Windows or aren't in a position to license commercial software in order to make screencasts. So in this column I'll focus on basic strategies that transcend specific tools. If you're on Windows, you might be using free stuff: Windows Media Encoder, or WME, for capture and Windows Movie Maker for editing. I haven't found a free capture tool for the Mac, but I have used WME to record Mac screen activity by way of a remote VNC session. For native video capture on the Mac I'm told that the relatively inexpensive Snapz Pro works well. Of course, iMovie, bundled with Mac OS X, is a capable low-end video editor. On either platform (and on Linux as well), Audacity is the cheapskate's weapon of choice for recording and editing audio narration.
In these scenarios you'll wind up producing either Windows Media (.WMV) or QuickTime (.MOV) files. Neither affords the simplicity of Flash (.SWF), the most universally accessible delivery format. But that may not matter crucially. Both Windows Media and QuickTime can yield compact, progressively downloadable files. And in each case there are freely available, cross-platform options: Windows Media Player for Mac OS X and QuickTime for Windows. Here's one way to think about the tradeoffs. If people like your screencasts so much that they demand more seamless playback, that's a good problem to have. You'll know that an investment in tools is justified. Meanwhile, focus on creating compelling content. To that end, here are some of the guidelines I've developed for myself.