/usr/share/doc/nfs-utils-<version-number>/ - Replace <version-number> with the version number of the NFS package installed. This directory contains a wealth of information about the NFS implementation for Linux, including a look at various NFS configurations and their impact on file transfer performance.
man mount - Contains a comprehensive look at mount options for both NFS server and client configurations.
man fstab - Gives details for the format of the /etc/fstab file used to mount file systems at boot-time.
man nfs - Provides details on NFS-specific file system export and mount options.
man exports - Shows common options used in the /etc/exports file when exporting NFS file systems.