Recently, I have been recommending Google's Technical Writing courses to new writers. However, I also find myself pointing out content gaps in the courses and sharing complementary resources. So I made a video to share my opinions and other resources:
TL;DW: The courses are designed to help engineers to improve their tech writing skills. I think the assumption is that the student already knows the technology they are writing about. IMO, the courses are an excellent starting point for new tech writers and they are even more useful when coupled with Google's developer documentation style guide and Divio's documentation framework. In the video, I also share how I would have used all these resources if I were a new tech writer. Hope the video helps you decide if the courses are worth your time!