I use these alot in my songs and are very common.
OH - Open High Hat - CH - Closed High Hat
CL - Clap (or Snare) BD - Kick Drum

http://mp3.com/ptx

  |Play 3 Times    | |Play Once       |
OH|--x---x---x---x-| |--x---x---x---x-|
CH|x---x---x---x---| |x---x---x---x---|
CL|----o-------o---| |----o-------o---|
BD|o---o---o---o---| |o---o---o---o-o-|

You can Also add stuff like RS\'s

RS|o-oo-o-oo-o-oo-o|