Dozens of easy-to-follow video tutorials for crochet and knitting, from the basics to advanced techniques.

Not a channel, but an interesting TEDx Talk by a Cornell mathematician. Full transcript is available on the speaker's blog: https://hyperbolic-crochet.blogspot.com/2012/07/my-tedxriga-talk-transcribed-full.html.

Another source for crochet techniques, with videos for left handers.

Subject index for the TECHknitter blog, with clear diagrams of various techniques, stitches, etc. Use CTRL + F to find your search terms within the index.

Videos on various knitting skills, in both Continental and English styles.

List of common pattern abbreviations, many with instructions, including links to additional resources, from the online magazine Knitty.

Fun blog post by an artificial intelligence expert about the problems neural networks have reading and processing knitting patterns.