The Tasks view is mostly self explanatory.  It is the central location to view, start, and cancel tasks.  There are a few things to note.  Users can only see tasks they have created, while administrators see all tasks.  Administrators have an additional option to cancel all tasks, that users do not.  Finally, when starting an On Demand multicast, there is a client count option.  If this is filled in, the multicast will automatically start when that number of clients connect to the session.  If the field is left empty, you will need to manually start the multicast from any of the clients.