SD.IncidentManagement Questions

I have some questions.

1.  Can someone tell me at what point in the IncidentManagementProcess the system creates the Incident Number and puts that info in the database?
2.  Also in SD.IncidentManagement can someone tell me how the subtask are created and get the .X subtask number for the main system?
3.  I checked out the Service desk components, but couldn't find one for adding a task to an incident.  If you know where this is can you tell me?

I'm trying to create some demo helpdesk stuff, but am have a hard time deciphering what the programmers were doing.
I'm very familiar with workflow, just having a hard time getting inside of how it's being used for the service desk.

Thanks