Gray just add the web service URL

sample :
http://www.demo.com/wcf/WebserviceV2.svc(.NET 3.5 Service)
http://www.demo.com/wcf/WebserviceV2.asmx (.NET 2.0)

Then you will add reference to the WS.

you then instantiate the object in you app. make sure you add reference to it
lets say

using WEBservice1



do stuff...