A quick look at this guide, which at the time of writing was free.
Click the cover to see this book on Amazon UK (affiliate link)
This book was available free of charge today as a Kindle version, so I thought “Why not?”. Although the title is slightly bonkers — ok, very bonkers — the content isn’t bad at all. The explanations are pretty good, and you can even try out the exercises online, as shown in the screenshot below:
HTML5 Practice, by Terry Freedman
I did spot a spelling error which wouldn’t have been picked up by a spellchecker, but apart from that the content is both comprehensive and accessible. I don’t know how much the book costs normally, but if you see this in time you may be able to grab a free copy.