Lingo:

C: control key (CTRL)
M: meta key (ALT or ESC)

Quick Answers:

C-x C-f: find file
C-x C-s: save file
C-x C-c: exit emacs

Cursor Motion
Amount Operation
Move Move Delete Delete
Forward Backward Forward Backward
Characters C-f C-b C-d DEL
Words M-f M-b M-d M-DEL
Lines C-n C-p C-k C-SPC C-a C-w
Sentences M-e M-a M-k C-x DEL
Expressions C-M-f C-M-b C-M-k C-M-DEL
Paragraphs M-} M-{ None None
End/Start of Line C-e C-a None None
End/Start of Buffer M-> M-< None None
Scrolling and Windows
C-v Page Down
M-v Page Up
C-M-v Page Down other window
C-x 1 Make current window only window
C-x 2 Split window vertically
C-x 3 Split window horizontally
C-x ^ Grow window vertically
C-x o Switch to next window
C-x 0 Close current window
Cutting and Pasting
C-SPC Set mark
C-w Cut (after setting mark and moving to end point)
M-w Copy (after setting mark and moving to end point)
C-y Yank (paste) most recently killed (cut or copied)
M-y Yank next most recently killed
Files and Buffers
C-x C-f Find file (or create if not existing)
C-x C-s Save file
C-x C-w Write file
C-x s Save modified buffers
C-x b Select buffer
C-x C-b List buffers
C-x k Kill buffer
 
 
Command-Related Stuff
ESC ESC ESC Leave current location
C-u # Prefix numeric argument # to next command
C-g Stop running command, or cancel partially entered command
 
 
Searching and Replacing
C-s Incremental search forward
C-r Incremental search backward
C-M-s Regexp search forward
C-M-r Regexp search backward
M-x replace-string RET String replace from here to end of buffer
M-x query-replace RET String replace from here to end of buffer, querying for each occurrence
M-x grep RET Prompts for a grep command, shows hits in a buffer
C-x ` Visit next grep hit
Help
C-h k Show command documentation
C-h a "Command apropos"
C-h c Show command name on message line
C-h f Describe function
C-h i Info browser
Misc
C-_ or C-x u Undo/redo
C-q Quoted insert
C-z Suspend/iconify emacs (type "%emacs" to return)
C-x C-c Exit emacs