I have learned Emacs mostly using it's own documentation and the late emacs-starter-kit. Talking with people interested in learning Emacs, I found that my approach is not appealing to them.
What are the best resources around to learn Emacs from scratch ?
Are there resources dedicated for people migrating from other editors (vim/sublime) to Emacs?
This is the place I suggest to start. It is a relatively organized set of EmacsWiki pages (category EmacsNewbie) for help with learning Emacs.
These are the pages in that set. And some of these lead to further pages. For example, you will most likely want to look at the LearningEmacs page. (And this page is about learning Emacs Lisp.)
How To Learn Emacs is something I wish I'd found years ago.
It's clear, concise, and a good introduction to using Emacs effectively.
The emacs guided tour is what I would recommend for new users who want to edit text ASAP. If you want to learn elisp, I think the Emacs Lisp Introduction available as an info node is easiest for getting your feet wet.
When I first learned emacs I followed the built-in tutorial. It is a good exposition of the most basic emacs concepts and keybindings. It is interactive in that it is an editable buffer that encourages you to try out the operations as you read about them including searching, text insertion/deletion, kill/yank operations, opening files, switching between buffers, splitting windows, and more.
One (arguable) downside is that it is a long (1,160 lines) text document with no pictures, so it may not be very appealing to people who are used to flashy animated tutorials with embedded videos, etc. Personally, I did not find it to be boring because it is fairly hands-on, and it takes less than an hour to work through all of the examples.
You can access the built-in tutorial by typing C-h t (which means Ctrl+h, then t).
