If I understand what you are asking for, you can do all this from the terminal window.
Terminal is located in applications/utilities
in the terminal window type (ignore the "") either
"top"
to see a general list of all process running on your system
OR
"top -u"
to see a list of all process running by their CPU usage
BTW: when viewing processes via top, you can type the letter q to stop top and return to the command line
After you have done this, you can stop a process by issuing the kill command. Although, I would advise that you learn more about Unix before messing around with Kill
David