Is there any implementation of the NFS protocol written in C# or a good documentation thats easy to read so I can implement my own..
Both server and Client are neede
I recommend starting with the latest stable source code of NFS, and then run it from Cygwin (see below). You would then start with a fully-functional well-tested NFS client and server, which you could then tweak as you desire.
Try this site: Cygwin NFS Server HOWTO