Emacs is the best editor I've yet found and here are some keys to get your started.
C-x means press and hold the Control
key and touch the x and then let go of both.
M-y means press and let go of the Escape
key and after you have let go of it then press and let go
of the y key. Alternative M-y can be
typed on some system by holding down the Meta (or
more commonly Alt) key and pressing the
y before letting go of both keys.
C-g Cancel (type several times to get out of anything)
C-x C-c Quit emacs (you will be asked if you haven't saved anything)
C-x C-s Save the current file (known as a buffer)
C-_ Undo (you might need to type this as Ctrl+Shift+Minus)