Files:
C-x C-f Reads a file into an Emacs buffer C-x C-s Saves the current buffer C-x C-c Saves all modified buffers and exits Emacs
Buffers:
In Emacs each open file is edited in a buffer.
Commands to switch between the different buffers
(there are also menu options):
C-x C-b Prints a list of the available buffers C-x b Asks you which buffer to select
Windows: Buffers are displayed in windows (you can also use the mouse):
C-x 2 Splits the current window vertically into two. C-x 3 Splits the current window horizontally into two. C-x 1 Deletes all windows except the one with the cursor C-x o Moves you into an other window on the screen