NIS is a protocol developed by sun to allow one to defer user authentication to a server. The server software is in the ypserv package, and the client software is in the yp-tools package. ypbind-mt is also available, which is a multi threaded version of the client daemon.
Note: obviously this article is far from finished. hopefully in the future that will change, but in the meantime:
The Linux NIS HOWTO (http://www.tldp.org/HOWTO/NIS-HOWTO/) is very helpful and generally applicable to arch linux.
How to Setup NIS client
First step is to install the tools that you will need. This will provide you with the configuration files and general tools needed to use NIS.
# pacman -S yp-tools ypbind-mt
Next add your NIS domain name to the file /etc/conf.d/nisdomainname
If your NIS domainname has not already been set you can run this command to set it.
# /bin/domainname nis.domain
Now edit the /etc/yp.conf file and add your ypserver or nis server.
# ypserver your.nis.server
Start the ypbind daemon.
# /etc/rc.d ypbind start
Add it to your rc.conf file if you want it to start automagically.