How to tell if Remote Desktop service is running and available?

You can use NMAP/Zenmap on your machine. Just point it at the server like so:

nmap -PN -sS -p 3389 ip-of-machine

Or you can use the GUI version, Zenmap and just plug all that in to the GUI.

Use Task Scheduler to trigger an event when the Windows Remote Management service is started.

Open Task Scheduler, click Create Task, Select the Triggers tab, and click New. Choose the Custom option under settings and click the New Event Filter... button. From there you'll need to drill down in to Application and Services Logs, Microsoft, Windows, and check Windows Remote management. Then filter by Event ID 209 (the service started event) and click Ok.

As for the action it triggers, I decided to use Blat and create a short batch file:

C:\blat\blat.exe -to [email protected] -subject "Server is awake" -body "WinRM started on %COMPUTERNAME%!"

You could configure all this using a GPO if you want this notification on multiple servers/computers. Keep in mind though it's going to send you this email every time the service is started, not just when the computer is rebooted. That could get annoying.