If you need to shut down you server and you need to notify your users of this you can send a message to there screen notifying them of a server reboot or shutdown. This article covers windows and unix /linux.
On a terinal or remote dekstop server there are various applications that yuo will not want a remote desktop user to run, regedit is one of them Here is how to stop a standard user from running regedit in terminal services.
If you want to control a pc remotely with RDP you may find that RDP is disabled, all is not lost. Here is a guide on how enable RDP remoteley when it is not enabled.
A guide on the procedure of installing and maintaing applications that are on a windows terminal server or a remote desktop server.