DarkRift's got a great community and great help available to all developers.
PDF documentation comes with DarkRift, along with all the example scenes, but you can always access the documentation here if you dont want to download DarkRift:
Embedded Server Guide
There's a few free plugins developed by me or the community floating around the internet. They're free to use and can give you a great starting point or leg up for your games:
Third Party Plugins
The best place for help is the Unity Community, I'm very active on the DarkRift threads. Alternatively you can email me if you want to get in touch that way or check out the FAQ for any commonly asked questions.