A list of courses available for learning the NetBeans APIs
- NetBeans Platform for Desktop Java Development (DTJ-2601) by Sun Learning Services
- NetBeans Platform Certified Training by trainers from the NetBeans Platform community.
- Eppleton 'NetBeans Rich Client Platform Development' by Eppleton in Germany.
- Orientation in Objects 'Entwicklung met NetBeans' by OIO in Germany.
- Seges 'NetBeans Platform' Training by Seges in Slovakia.
In addition, several screencasts and tutorials on platform.netbeans.org are specifically focused on getting you started with the NetBeans Platform, such as the Top 10 NetBeans APIs series. Also, a course on javapassion.com is forthcoming.
There are probably more. Please let me (geertjan DOT wielenga AT sun DOT com) know if anyone knows of others.