set mark and point around current line

[Baloff]

Hello
how can I find out what is the command to do somthing.
say I want to select "highlight" the current line to copy it to another 
window.
do I (Set the mark and point around the current line) > M-w > change 
window > C-y?
and btw, when you have many windows open, aren't they numbered so that 
you can issue a command to go to a spacific window instead of what I am 
doing C-x o and watch the pointer move randomly till it gets to the 
window of my choice.

thanks