I learned emacs from the version of this book available in 1999. I don't think much of what I learned is hopelessly obsolete. Basics are basics.

I felt the book was a nice overview, both covering the basic terms and techniques and giving a tour of important features like dired and in-emacs shells. You'll want to augment by reading other online sources (there was no emacswiki in 1999, that I knew of) but the book is probably still worth the money. This is emacs. You'll appreciate having more than one tour guide, because the world is big and everyone knows one part better than others.