Hi Rajan,
Don't expect a document describing the steps to build your application.
The error that you are getting is not even a JBPM error, it's a JPA one, so you can try to find out what's is happening. Usually you get that error when you don't have Hibernate or any JPA provider inside your application classpath. Are you using Maven? if not you will need to add hibernate and all its dependencies to the classpath.
Cheers