I haven't written much on here about RSDNS as I'm trying to keep everything in the github ecosystem.
Currently there is no web-page-documentation, forums or wiki's. RSDNS usage is all documented in the README.md which should be the fist place to look if you want to get started. If you have a problem post an issue, if you can fix a problem raise a pull request.
All community contributions are greatly appreciated, happy RackSpace DNS everyone!