Emacs Quick Reference

Lines
C-a             beginning-of-line
C-e             end-of-line
C-k             kill-line
Characters
C-d             delete-char
DEL             delete-backward-char
Regions
C-SPACE         set-mark-command
C-w             kill-region (between cursor and mark)
ESC-w           copy-region
C-y             yank (paste)
ESC-y           paste the prior thing pasted (after initial C-y)
Also, use mouse to select region, then C-w, ESC-w (or DEL). However, DEL does not put things into clipboard so no paste.

Click on scroll wheel to paste.

UNDO
C-x u             undo
Search
C-s             isearch-forward
C-r             isearch-backward
Files
C-x C-f         find-file (open)
C-x C-w         write-file
Windows
C-x 1           remove splits of windows
C-x 2           split-window-vertically
C-x 3           split-window-horizontally
C-x o           other-window (useful in ssh window) 
Miscellaneous
C-x C-c         save-buffers-kill-emacs
C-z             suspend-emacs
                (resume by typing "fg" to unix)
Help!
C-g                           keyboard-quit
ESC-x man RET RET             man page for word cursor is on
ESC-X man RET 3 printf RET    man page for (for example) C printf