Ticket management workflow

We are in the mid stages of implementing SDP. I am uncertain the best way to manage "tickets" in SDP. For example, our current process is this:

End user submits ticket to Help Desk via email. Tickets can be for anything that requires IT assistance. This means that a ticket might be anything such as a problem with a printer, new software request, conference setup or anything in between.
Ticket is automatically created in help desk software with pending assignment status.
Help Desk coordinator assigned Technician to work the ticket and Tecnician gets an email with assignment details.
Technician works the ticket and replies to the assignment email with status updates. The helpdesk software reads the email and updates the ticket accordingly.
Step 4 can repeat often.
When work on ticket is complete, Technician log into the help desk software and closes the ticket.

May questions are:

How are tickets supposed to be worked in SDP and can you point me to a workflow diagram?
How can you assign multiple Technicians to a ticket?
If a ticket has multiple Technicians, how can you mark one a the primary Technician.

Sorry for the noob questions.