Emacs Quick Reference (for version 19)
"C-" (control) means "hold down Ctrl key"
"M-" (meta) means "hold down Alt key", or "press and release Esc key"
Category Command Keystrokes Mnemonic
Start/Stop start emacs from DOS emacs  
exit emacs C-x C-c  
Files read a file into Emacs C-x C-f find
create a new file (name it as if it exists) C-x C-f  find
save C-x C-s save
save as ... C-x C-w write
Cursor  Motion forward (right arrow) C-f forward
backward (left arrow) C-b backward
up (up arrow) C-p previous
down (down arrow) C-n next
jump to start of line C-a a = start alphabet
jump to end of line C-e end
jump to start of buffer M-< < = left
jump to end of buffer M-> > = right
Cut, Copy, Paste

"kill" = "cut", 
"yank" = "paste"

delete current character C-d delete
delete previous character Delete or 
kill to end of line C-k kill
kill region C-w wipe
copy region M-w  
yank back last thing killed C-y yank
replace last yank with previous kill M-y  
Marking Regions
"region" = text between "point" (cursor) and invisible "mark"
set mark here C-SPACE  
mark entire buffer C-x h  
Formatting indent current line TAB  
indent entire buffer M-p "pretty-print" (non-standard)
fill paragraph M-q  
Buffers cycle through buffers C-j jump (non-standard)
shell (command) buffer  C-z (non-standard)
list all buffers  C-x C-b buffer
close a buffer C-x k kill
Error  Recovery abort partially typed or executing command C-g  
undo an unwanted change C-_  undo
restore a buffer to its original contents M-x revert-buffer  
The  Minibuffer complete as much as possible TAB  
complete up to one word SPACE  
Type C-x ESC ESC to repeat the last command that used the minibuffer.  Then the following keys are defined. previous minibuffer command M-p previous
next minibuffer command M-n next
Multiple  Windows make one window C-x 1 one
delete this window C-x 0 zero
split window vertically C-x 2 two
split window horizontally C-x 3  
switch to another window  C-x o other
Incremental  Search
Then type a word to search for.  Use C-s or C-r again to repeat the search in either direction
search forward C-s search
search backward C-r reverse
exit search Enter  
Query  Replace
yes = "y" or SPACE,  no = "n"
interactively replace text M-%  
Directory Editor
find directory (C-x C-f . ), then "?" for help
list and manage files    
Help help C-h help
show function a key runs C-h k key
describe a function C-h f  function
tutorial C-h t tutorial