I'm new MassTransit Service Bus. What are the options to configure service endpoints besides in code or appSettings in a config file? And what is the preferred method?
Normally you would just subscribe to a given type via consumers and have publishers. There is not normally any coupling between them other than the message type. So the connections between endpoints or more or less automatically configured based upon metadata.
The documentation on subscriptions configuration might be a good place to start to dig into this a little more.