Bash Hackers Wiki
The Bash progamming language is surprisingly flexible.
"The Bash-Hackers Wiki is intended to hold documentations of any kind about the GNU Bash. The main motivation was to provide human-readable documentation and information to not force users to read every bit of the Bash manpage - which is hard sometimes. However, these docs here are not meant as newbie tutorial."
This wiki has many how-to pages with specific code showing how to do many common tasks with Bash scripts -- using getopts, Debugging a script, Lock your script (against parallel run), tips for making portable scripts, system administration, etc.