I myself have discovered everything I know along the way, and have read no guides, so unfortunately don't know any of them. Tho C-h t is the unavoidable initiation to emacs the editor.

Using tools lik Org mode, Rmail, Elfeed etc. gives you many opportunities to write some useful elisp, which is a pedagogical experience.

Emacs is like the mildly beautiful geeky girl which you fall in love with: whenever she spots you inclined to some new cute girl, instead of going mad with you, reveals such a wonderful piece of her interior world that you just forget the other one :)