Reading, by very very large margin. Videos are difficult for me to learn from in part because they have a very low information density, in part because it's much harder to "back up" and review specific things or to "look ahead" to preview what's coming, and in part because I have a terrible time absorbing factual information verbally.<p>When I'm looking for instruction, I ignore video versions of it and only go to those if I can't find written ones.
Text with photos / illustrations / images - however there's a lot of poorly put together attempts to be instructional, including books that appear to have had the necessary proof reading, sub editor etc since the topic would expected to be out of their field of "in depth" knowledge. I prefer a good book, but have paid out (long ago) for stuff that I could have copied out of stock standard books that cover similar or written off the top of my head and got a few technical details from the supplier.<p>Video usually wastes 10 minutes that could be explained with a thorough text description with photos, but sometimes, it's the simplest way to ensure people haven't missed an important step. If it works in video, it should work the same for those who can duplicate the steps. I've had to refer to a few videos for pulling certain bits apart without destroying them, where the text was really written for the technician who do different brands or models all day long.
I don't have the patience to get actual information from a video or audio presentation, usually.<p>TV/Movies are worth paying slightly more attention to the first time you see them (if you're lucky); thereafter "background".<p>There's been articles recently about major publishers telling content creators to <i>aim</i> to be background content. I think that reflects that they see the reality of how people <i>use</i> these media more than "they don't want intellectually challenging content to be made."