Here is a simple one: Copy and paste from one program to another program, ( your browser to a text editor, from one desktop to another, from a text editor to the console/terminal etc.etc. )
Just elect the text with your mouse ( this copies it automatically to the clipboard ) go to the other screen and push the wheel ( or middle button ) that pastes it.
So only two movements . . no context menu . . just select and paste.
The only exception is OpenOffice, there you will have to do in like you do it in Windows: select, rightclick, choose copy from the contextmenu, rightclick and paste it from the context menu.
Sure the keyboard shortcuts Ctrl+c and Ctrl+v work in Linux too
In most distro's you will find a clipboard next to the clock ( an orange icon with a K ) . . . it remembers the last 5 entries ( or more if you configure it that way ) . . . simply tick the entry you want to paste and pushing the wheel will paste that entry where you want it.
If you want to copy a full config file to a textfile that you can send as a mail-attachment, one command will do: ( example the lilo.conf file )
# cat /etc/lilo.conf >lilo.txt
This will put a text file in your /home directory by the name of lilo.txt