It's been a while since I used a Mac but my recollection is that the same Emacs style key bindings were available for all text fields pretty much without exception.
That said, on Windows and in Linux this is extremely much simpler and more consistent, I can write it down right here and now, it doesn't need a full web page:
arrow keys: move
ctrl + arrow left/right: move left/right to next word boundary.
shift + arrow left/right: select a character to the left/right.
ctrl + shift + arrow left/right: select to next word boundary.