I've worked with or on several APIs over the last few years, and it's quite frustrating how many of them have subpar documentation. It's not entirely surprising because making good API documentation takes a bit of work, and many companies don't prioritise it enough to put in that work.
Well, I'm hoping I can change that. I made a video course, apidocsfordevs.com.
Over 5 hours of video content, taking you from the philosophy and mindset of great API documentation to actually documenting a couple of APIs with me. Concepts are demonstrated with real-world examples and exercises, and I've included a bunch of tips and external resources as well to improve your writing skills. The videos also have text summaries if you just want to grab the concepts quickly. I hope you find it helpful.
PS. Also launched on ProductHunt.