Pointers to some education and code for server to web communication

I'm using .net in azure, and I'd like to ask/offer for assistance in orienting myself to a task. The task is quite simple: I want to create a service on a windows 2012 server which my website can use to communicate with my server. Any simple demonstration of opening communication with a service running on the server will do (but ideally  the approach will use current environment and be one that I can later develop for richer communication including wpf, chat and video stream).

So, the highest dream of what would help me, is if an expert who does this programming in C# can point to a tutorial that demonstrates building this, or who can pop off some extremely crude code, that just opens communication between the website and the server, just a "hello server" demo, that can also say "sorry, server is not answering". And a separate program that runs on the server. I know nothing about this server side communication service, and am interested in knowing how I can set up a wpf service that responds to queries from the website.