The tutorial doesn't cover all of the sample applications found in the examples directory. All of the examples include detailed README files and well-commented code. In addition, certain topics can be found elsewhere:
Notifications are well covered in the JMX instrumentation specification
The MBean registration process is covered in the JMX agent specification
Proxy MBeans are introduced in Getting Started with the Java Dynamic Management Kit 4.0
The monitoring and timer services are covered in the JMX agent specification