What you try to migrate?
Only deploy you J2EE application in a JBoss6?
AFAIK a migration document or tutorial does not exists
It should be simple if you use only the J2EE specification and no JBoss enhancements or break the spec rules.
Unfortunately former JBoss versions did not validate deployment descriptors and configuration.
With JBoss5 this was an issue and I suppose with JBoss6 also.
I start with a plain JBoss and deploy configurations and resources first, then the different application components.
In this case it is easier to find the deploy problems.
See if this helps: http://www.coderanch.com/t/517946/JBoss/Migration-jboss
That link discusses migration from 4.0 to 5.0, but the principles still apply. Note that 6.0 uses HornetMQ for messaging, so the specifics on updating messaging are different.