Reference Sheet by Alex Schroeder

Files, Buffers, Windows
C-x C-f Find file (“Open”)
C-x C-s Save buffer (“Save”)
C-x C-w Write file (“Save As…”)
C-x 2 Split window
C-x 1 Delete other windows (“Unsplit”)
C-x o Other window
C-x C-b Buffer menu
Search and replace
C-s Incremental search string forwards
C-r Incremental search string backwards
M-% Query replace string
C-M-s Incremental search regexp forwards
C-M-r Incremental search regexp backwards
C-M-% Query replace regexp
C-a Beginning of line
C-e End of line
C-k Kill line (“cut line”)
M-b Backwards word
M-f Forwards word
M-d Kill word (“cut word”)
Balanced expressions such as “foo” or (foo)
C-M-b Backwards sexp
C-M-f Forwards sexp
C-M-k Kill sexp
Region (between mark and point)
C-SPC Set mark
C-w Kill region (“cut”)
M-w Copy region (“copy”)
Pasting, Undoing
C-y Yank (“paste”)
C-y M-y Yank older copy (M-y…)
C-_ Undo, anything else interrupts the undo chain
C-x r k Kill rectangle
C-x r y Yank rectangle