I know that on-line, electronic documentation is all the rage. You can barely find a software package that comes with a book any more, and even the companies that provide the books are moving to on-line services (like Safari).
But at heart, I'm a dead tree doc guy. I'm not the first to talk about this. The fact that there is a series of books called "Missing Manuals" shows that the tangible book isn't on the endangered list by any means.
What made me think about this is an experience I had yesterday. I was having a small problem with DBI and started reading the perldoc. I couldn't find the right info, so I pulled down my Perl DBI O'Reilly book. The text was exactly the same, but scanning the book I found my answer right away when I didn't see it on the screen.
My original training as an English major has probably forever trained my brain to read a page better than a terminal. The tactile experience of the book also seems to help me. No, I can't type a quick search, but my lizard brain seems to be able to remember from feel about where key information is in a book if I've been there before, and I can turn to it quickly. I'm sure some computer people are the opposite and prefer the electronic search.
Either way, the on-line revolution can make you feel like the last person reading actual books, like James Kirk with his old, cracked glasses.