If you are not able to click these links, simply copy them into your browser. 

https://github.com/joomla

Platform code GIT Repo - Join in the fun and fork Joomla then ask for a pull

http://developer.joomla.org 

Join the developer Mailing list and see resources about the Joomla Framework

http://www.cloudaccess.net/free-joomla-training-webinars.html 

Daily Free Live Getting Started Joomla community Webinars