This is from a Flash tutorial called Learning Flash in a Flash (Episodes 2 and 3) from the Flash Developer Center.
I usually prefer to watch a video or a demonstration rather than read text or annotated text, because it's easier and faster for me to see what's going on and follow along. But, while I'm following along, I want to be able to pause the video when I lag behind, or repeat a section that I didn't quite understand.
This tutorial was good in that sense, but it had some annoying problems. The files that I downloded for the tutorial didn't exactly match the tutorial. One file had a white box around the character, that just magically disappears in the tutorial; it took me a lot of time to figure out that there were multiple versions of the file and they were referencing the wrong file in the video.
And although you are supposed to use a sound file in the tutorial, one is not provided. So, I had to track on down from a free sound effects website.
It's interesting that much of the video is a "talking head." The instructor provides a lot of background information and explanation face-to-face. Although, I typically dislike talking heads, seeing the instructor actually made the video easier for me to follow.