Movement
Home Move to the start of a line
End Move to the end of a line
Ctrl-> Move right one word
Ctrl-< Move left one word
Ctrl-End Move to the end of the file
Ctrl-Home Move to the begging of file
Ctrl+F Find in Message
Ctrl+G Find Again
Ctrl+Shift+N Blank Page in Composer

Selection
Ctrl+A Selects all the text on a page
Ctrl+C Copy Selection
Ctrl+V Pastes a selection that you've copied
Ctrl+X Cuts a selection
Ctrl-Shift-> Select word to the right
Ctrl-Shift-< Select word to the left
Ctrl-Shift-end Select to the end of the file
Ctrl-Shift-home Select to the beginning of the file
Shift-end Select to the end of the line
Shift-home Select to the beginning of the line

Formatting
Ctrl+B Bold
Ctrl+E Center
Ctrl+I Italic
Ctrl+K Remove all styles
Ctrl+L Left Justify
Ctrl+Shirt+L Link
Ctrl+R Right Justify
Ctrl+U Underline
Ctrl+Z Undo
Ctrl+= Increase indent
Ctrl+- Decrease indent
Shift+Enter New Line Break <br>