@DMichael: Oh, those contain nice stuff as well. I think books are relevant as well: Since videos are done live, it is quite likely that the authors overlook somethings or forget to say something relevant. I have done some written tutorials and video tutorials in the past. And the videos were always easier for me (press record and talk) but I must admit I wasn't as good as the written tuts. But whatever, maybe it was just me, hehe
Anyway, it's also required to pay a lot of attention to everything that goes on the screen (sometimes is too slow, and sometimes too fast) whereas with books/ebooks you can go at the speed you want, and basically read them everywhere. :-)