Here is som usefull commands to master screen in a shell.
More info at

To start screen :

All screen commands start with :

To Open a new screen within the screen session:
Ctrl-a c

To switch between open screen's:
Ctrl-a a to last accessed screen.
Ctrl-a n to next.
Ctrl-a p to previous screens.

To disconnect with out stopping your processes:
Ctrl-o d

Full list of commands :
Ctrl-a ?

To reconnect to a screen again :
screen -r
screen -r -d (reconnects to master screen)


--- More to come ---