Hi Dee, although you requested information on how to guides, allow me to recommend two O'reilly reference books which might help in the future. The first is Practical UNIX and Internet Security, this book has a comprehensive section on NFS. The other is UNIX Power Tools. You should be able to find both on the internet in PDF format. I have dog eared paper copies but I recall being able to find copies for others on the net.
Personally, I find a little peripheral reading from a historical context to be quite helpful in troubleshooting setups.
Hope this helps.