I will go one step further than Bear, even. For learning, I still prefer Dead Tree books to ebooks. While you cannot do an automated search of paper pages, I find them easier to scan randomly and things just jump out at me. I learn a lot that way.
Also, a book still works when your Internet connection is down.
And the data contained in a book is consistent. If you pop around the Internet randomly, you'll end up with information of various vintages. Some of which is obsolete, but since often web pages carry no datestamp, it's hard to tell. It took
years for me to stop seeing questions on the
JSF forum relating to practices that had been obsoleted by even the 1.0 release.
As it happens, I have a rather old HTML4/CSS book that I keep close by and it's my primary go-to, even despite its age. I know where what I need is in it and can get there faster than you can say "Google Search". I also have an O'Reilly pocket guide, but the book goes into more detail when I need it.