I've built a NIS network at my office from scratch. Look into using AMD (Auto Mounting Daemon) with NIS. You'll also need to configure NFS.
To explain things in a short version.
Share out your password, group, and hosts file with NIS
Create a NIS map that maps to the users home directory and push it out to the clients via NIS
Share the users directories using NFS (exports file located in /etc)
Move the Users Home Directory to a different location (suggestion /local/home)
Make sure your NIS maps point to this location
Remove the default home directory and configure AMD to recreate and automount it
That should do it.
To fix your problem with KDE make sure KDE 3.2 is installed on each machine that you want to use it on.