Type this into your terminal: emacs
On a more serious note, do please feel free to give any and all helpful advice on how to get started with emacs. I'm okay with vim, I've been using it more and less for about 2 years, but emacs has always seemed more esoteric and I never did quite get the hang of it.
Find ways to do as much as you can of what you normally do with your computer in emacs. If you use IRC a lot, use erc. If you use email a lot, try out gnus or rmail. Don't try to replace your web browser with w3m, that's just stupid and you'll hate it.
Also, find a mode you really like. This will keep you using emacs whether you like it or not, until you really do like it. For me, it was gdb-mode. For most, it's one of the inferior repl modes (slime for lisp or clojure or whatever, ruby, python).
I've heard good things about http://github.com/technomancy/emacs-starter-kit, but I've never tried it.