(1) what needs to be specified in the client gui for the dialog boxes for networked server parts? E.g. port number, etc.
(2) I presume the networked server must be started before the networked client?
Champion, for your first question, please take a look here. But you may want to include the server's IP address and the port number in which the server is running.
For your second question, exactly. If you start the application in client mode, and the server is not running, then you may considering showing a message to the user, saying that the server could not be found.