Do you have to use multiple terminals while working on console, then screen is the utility for you.
Now you would like to login into screen by default so that you dont have enter the screen command every time you start a new bash. For this all you have to do is enter a line
screen -x || screen
in your .bashrc or .bash_profile file in your home directory.
.bashrc is executed every time you start a console. So adding the above line in .bashrc file executes the above line every time .bash is started. above line just checks if there is already a screen opened on the system. If it is opened, it connects to that or else it starts a new screen.
