Need help Random timeclock

Looking to make a random timer event ie/switch an output between 3 and 30 minutes then loop again anyone able to start me off as new to this Thanks Terry

and this - http://www.arduino.cc/en/Reference/Random -

and this - http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1201656636 -

Thanks will give these a try looks like a good start