Hi, since you're a newbie to this field, you first need to understand the concept of a WCF (Windows Communcation Foundation) and the client (which in your case is a website). First step is to create the service, which in real is an interface to be implemented by a host. The host can be anything that can accept the requests from clients; in most cases is just a Console application. Then you will create a simple library, which will be used to implement the interface of your service, and add the functionality to it (if you've got the empty functions in your interface then you need to declare them too).
Once done, you can simply just use those services (Add service reference in your website) in your website, to consume those service libraries. Once added, you can then follow on to use those resources and call the methods to perform different tasks.
Read my article on this topic, and download the sample if you want to test this functionality. Creating a Web Service to be consumed by connected Devices via Internet