Initial Device Setup
To set up the device itself initially follow the instructions it came with. In general you will download an app to your phone / tablet that will be used to configure it for your network. Some tips that I have found are that the device running the app must be on the same wireless SSID as the device. If it can't find the device, they do have an AP mode process that works pretty well.
RM Bridge App
Once it's configured for your network, download the free "RM Bridge" app from Google Play (make sure you are putting it on the Android device that will stay on 24/7). Installation is simple, it should find the RM Pro quickly. There's just a button saying 'Start' to start the server. It will show the IP address and port that you will need to use in the DashRunner configuration.
In DashRunner, click Config > Broadlink RM. Enter the IP address and port from the previous step, then click 'Load Devices'. It should find one or more devices (mine showed a Smart Plug and a device with a Chinese name) Select the correct device (if 'Smart Plug' is an option, chose the one labeled ID1 or similar).
To learn a command from a remote control, just click the 'Learn' icon and follow the directions. (Basically you will point the remote at the RM Pro, press a button, etc.) Once this is done, you can click 'Test' to have the RM Pro send the command to the device you are trying to control.
Add any remaining commands that you would like to be able to use in DashRunner.