I learned Emacs last year from the O'Reilly book, "Learning GNU Emacs" - http://www.amazon.com/Learning-Emacs-Third-Debra-Cameron/dp/...
It's an excellent reference and introduction. I also blindly followed Steve Yegge's advice here too, which turned out to be great: http://sites.google.com/site/steveyegge2/effective-emacs
One great source of Emacs knowledge: http://www.emacswiki.org/
I'm sure there are other info sources, but the wiki has proven to be incredibly helpful for me over the years.
I found that Meet Emacs from the PeepCode series was pretty good, and takes you a bit further than just the absolute basics. He also has a nice fork of emacs-starter-kit on Github.
One way is to commit to using emacs for everything, now, and then slowly 'dig your way out'.
That is how I had to start. I just decided I would use it and be completely overwhelmed for a couple weeks. It also helps if you have a proficient Emacs use sitting nearby that so that you can constantly ask how do things.
This is how I learned Emacs, LaTeX and Linux. It works, but only if you enjoy the process of everything being broken always.
I learned Emacs about 7 months ago. I would say that spending a little bit of time experimenting everyday with it is probably the way to learn new functionality. But I think learning Elisp definitely improved my usage of Emacs because it lets you understand why Emacs does what it does.
It's hard to get a sense for the "overview" of what emacs is about - what you should learn first, how to customize your setup, and where you should go next. It feels like walking in to a party full of really really really smart strangers.
Like a party full of smart strangers, once you get going it's fine... but most people don't stick around that long.