Mura Plugin Resources
Here are some great links to get you started in creating your Mura plugins. Feel free to add more links via the comments for at the bottom.
From the Mura site
Mura Docs - Plugins and Events
Mura Show Archive - Great Web-Casts About the Mura Platform
Bob Silverberg's excelent series on extending Mura with plugins
Extending Mura CMS with Plug-Ins
Extending Mura CMS with Plug-Ins - Part II - Hello World
Extending Mura CMS with Plugins - Part III - Configurable Settings
Extending Mura CMS with Plugins - Part IV - Using Extended Attributes