Drupal 8 Updates and How to Help
https://drupal.org/community-initiatives/drupal-core
Using Drupal 8's new route controllers
http://previousnext.com.au/blog/using-drupal-8s-new-route-controllers
Drupal 8 Module Development, Part 1: Getting Started
http://getlevelten.com/blog/ian-whitcomb/drupal-8-module-development-part-1-getting-started
Drupal 8 Module Development, Part 2: Forms