While I am also still in the learning process and have tried many different learning paths in my journey I can recommend you the way that helped me to gain the most:
This is ofcourse individual but i would not recommend starting from a book. For me it was just too much theoretical material and I was exhausted before I reached to the practical part at the end of the chapter.
What worked for me:
1) Dive into some online tutorials that teach you practical things like mocking up a Photoshop layout and turning it into HTML/CSS so you can actually "touch" something you make.
There are plenty of very good online step-by-step tutorials that let you download the final result as well so you can compare it to your own result. Of course if you are new in the field you do not
understand most of the things but if you have a basic knowledge about HTML/CSS and preferably Photoshop as well then it is okay.
2) In my case, understanding came a bit later After I had completed some tutorials and THEN I went to read some books in order to get some theoretical knowledge about
the selectors and properties that I typed in and what made up the complete website. Because I wanted to know of course what I was actually doing there. But I don't think you should
know the history of every tag and selector in order to get going.
3) don't use WYSIWYG editors