There is a little bit of documentation that comes with the OrionSDK. I believe the default path to it is C:\Program Files (x86)\SolarWinds\Orion SDK\Documentation\Orion SDK.pdf. There are a few examples in there that might be enough to get you started.
From what I can assume, yes, you can use it to add nodes to solarwinds. We've been able to do it with the powershell commands, it shouldn't be too difficult to convert them to REST. That's not currently a priority for us at this time, so we have not yet looked into it.
