Getting started on learning, really, really learning emacs is not, in and of itself, that hard, but will be markedly different from almost anything you’ve done in Word, Notepad, or any word processor you’ve used in the last ten years. Especially if you’ve started out on Macs in the first place.
You’ll have to unlearn a lot that you “know.” Also, if you’ve used other high-end text editors like BBedit, you’ll find some features not available right away out of the box.
As usual, the best way to learn is to actually do it.
A good site to learn more about about emacs as you get started is the Emacs Wiki. The site includes all sorts of information, including where to get different versions, and how to setup certain features. They also have an excellent page on where to get and set up Mac versions. I recommend you download the version compiled by Vincent Goulet because it includes several common packages and needed adjustments to work smoothly with the MacOS clipboard, and then that you skip on to do the tutorial.
The tutorial? Emacs is ‘self-documenting,’ and includes an excellent tutorial that leads you through the basic commands to move through a document and modify it. To start the tutorial, first start up emacs, and then type CNTRL-h (hold down the control key and press ‘h’, often referred to in emacs as C-h), followed by a ‘t’.
I’ll be back later to work around some things I missed from using BBedit and TextMate.