It seems that Ubuntu team is finally working on creating a good environment for new as well as experienced developers. Currently Ubuntu teams are conducting a series of workshops on development of apps in Ubuntu. The workshops are conducted via Google+ hangouts. You can also view them live in Youtube.
The next Ubuntu App Developer Showdown workshop is scheduled to take place on Monday, 25th of June, at 15:00 hours UTC and will cover things like Building Unity Integration of your app, Ubuntu One Integration, adding multimedia and social media support and also an hour of Developer Question & Answer session. These classrooms are open for anyone to join by visiting this page.
More advanced topics such as advanced GTK, multiple language support, Testing and Submitting your app, will take place on 26th of June starting from 15:00 hours UTC.
In case you missed previous classrooms, you can view them online on YouTube. If you are planning to head start with Ubuntu application development, this will be the perfect opportunity for you. Head over to this page to watch videos on basics topics such as Introduction to Python, GTK3, Getting started with Quickly, Glade, Launchpad etc.