Anthony Tedjamulia has a nice post on What I Wish I’d Known About Emacs. If you’re an experienced Emacser, you won’t find much that you didn’t already know but if you’re just starting with Emacs it’s an excellent orientation. One nice thing is that it explains the terminology that Emacs uses. I remember that I kept getting hung up on “yank” because its meaning was exactly the opposite of the way Vim uses it.
Another point that Tedjamulia makes is that Emacs is not so much an editor as a programming environment. Although Tedjamulia doesn’t say so explicitly, that environment is, in fact, a sort of Lisp Machine environment. He compares it to MS Office, an unsavory comparison to be sure but one not without merit. The idea is that Emacs provides a framework in which you or others can write applications. Notice that those applications don’t necessarily involve editing text. You can play music, chat on IRC, handle your email and many other things all because Emacs provides a framework which makes it easy to implement these things.
The final point that Tedjamulia makes that’s worth mentioning is that Emacs is completely transparent. As he puts it, everything is discoverable. You can easily query the documentation for any function, variable, or key sequence. If that doesn’t answer your question, you can follow the link to the source and see for yourself what a function or variable does. Everything is there for you to learn from or extend.
Tedjamulia’s post is, I think, a valuable resource for those new to Emacs. If you’re just starting out, or want to, give this post a read.