The NRC Preferences are well-explained in the interface:
If you tick the first two boxes here you can have an automatically-fired renderfarm. In Layout, on the Render tab there is a command Send to NRC. Loading a scene in Layout and setting it up for a network render then hitting that button will result in your scene getting "sent to the farm" and rendering starting leaving Layout free to carry on. No more waiting for a render before you can carry on working.
Scenes sent to NRC through Layout should be in complete content directories, otherwise the NRC Scene Content Directory entry won't be filled, and nodes won't get assigned scenes or automatically start rendering
Scenes can have their path settings overridden by the options here.
The Organize output into subfolders by task name option will render the auto-assigned Output path unique per task by appending the task name. Output for the task will then go into that subfolder in the common output path to avoid name collisions (and likely file overwriting). It only applies when the Output auto-assign option is enabled.
This option, enabled by default, means that right-clicking on a selected scene while it is rendering will give you a preview of frames completed.
The Render Output will only be available if all the following conditions are met:
The Controller can be configured to watch a folder for submissions (from the Layout "Send to NRC" script). The Controller must be running, and that folder setting must have been written into the Controller's config so the script can read it and know where to send scenes for rendering. There is an option to remove finished scenes. This kind of automatic setting is best used in conjunction with the settings on the Tasks tab.
The next tab is for Discovery. By default, NRC uses the Bonjour service for discovery but you can turn this service off (a restart of the NRC controller is required) if for some reason Bonjour fails to operate properly or you would rather use a standard IPv4 way of locating nodes. A default port number is provided.
If this number is not suitable for your network, render nodes will need to be reinstalled with an appropriate port number chosen during installation in the advanced NRC options.
If you have turned off Bonjour, a new button appears in the Controller window to manually force a scan for IPv4 nodes. The Controller will broadcast a scan when it starts. If new Nodes come online while the Controller is running (and you're using the IPv4 discovery mode), you'll need to rescan to discover them, unless you restart the Controller.
The last tab relates to NRC Interface options:
The options provided deal with minimizing the window to the task bar on minimize or close.