A basic skeleton bash script with a usage statement

skeleton.sh

#!/bin/bash
##
## Skeleton Script that does nothing useful.  This is the script that I copy
## when I make other scripts.
##
## Usage: _PROG_ [OPTIONS]
## 
## Options:
## -h --help		Display help message and exit
##

prog="$0"
me=`basename "$prog"`
dohelp(){
  grep '^##' "$prog" | sed -e 's/^##\s\?//' -e "s/_PROG_/$me/" 1>&2
  exit
}
if [ "$1" = "-h" -o "$1" = "--help" ] ; then
  dohelp
fi

# Do the script

For some more details on this method of self-documenting bash scripts, see this article from Linux Daily: http://www.thelinuxdaily.com/2012/09/self-documenting-scripts/